CompTIA A+

Preboot Execution Environment (PXE)

Technology that enables a PC to boot without any local storage by retrieving an OS from a server over a network.

Global Positioning System (GPS)

Technology that enables a mobile device to determine where you are on a map.

joule

Unit of energy describing how much energy a surge suppressor can handle before it fails.

kill

Unix-based command used to terminate a process.

spam

Unsolicited e-mails from both legitimate businesses and scammers that account for a huge percentage of traffic on the Internet.

social engineering

Using or manipulating people inside the networking environment to gain access to that network from the outside.

retinal scanner

Biometric security device that authenticates an individual by comparing retinal scans. Rarer in the real world than in media such as movies or video games.

image file

Bit-by-bit image of data to be burned on CD or DVD—from one file to an entire disc—stored as a single file on a hard drive. Particularly handy when copying from CD to CD or DVD to DVD.

sprite

Bitmapped graphic, such as a BMP file, used by early 3-D games to create the 3-D world.

BD-ROM (Blu-ray Disc-Read Only Media)

Blu-ray Disc equivalent of a DVDROM or CD-ROM. (See Blu-ray Disc.)

BD-RE (Blu-ray Disc-REwritable)

Blu-ray Disc equivalent of the rewritable DVD, allows writing and rewriting several times on the same BD. (See Blu-ray Disc.)

BD-R (Blu-ray Disc-Recordable)

Blu-ray Disc format that enables writing data to blank discs.

security token

Devices that store some unique information that a user carries with them. May contain digital certificates, passwords, biometric data, or RSA tokens.

dxdiag (DirectX Diagnostics Tool)

Diagnostic tool for getting information about and testing a computer's DirectX version.

contrast ratio

Difference in light intensity between the brightest white and the darkest black a monitor can produce

resistance

Difficulty in making electricity flow through a material, measured in ohms.

factory reset

Erasing all of the information stored on the device in an attempt to restore the device's software to its original manufacturer settings.

General Protection Fault (GPF)

Error code usually seen when separate active programs conflict on resources or data.

Boot Configuration Data (BCD) file

File that contains information about the various operating systems installed on the system as well as instructions for how to actually load (bootstrap) them.

FAT32

File allocation table that uses 32 bits to address and index clusters. Commonly used with USB flash-media drives and versions of Windows prior to XP.

read-only attribute

File attribute that does not allow a file to be altered or modified. Helpful when protecting system files that should not be edited.

container file

File containing two or more separate, compressed tracks, typically an audio and a moving picture track. Also known as a wrapper.

ext4 (Fourth Extended File System)

File system used by most Linux distributions.

transmit beamforming

Multiple-antenna technology that adjusts the signal when clients are discovered to optimize quality and minimize dead spots. Used in many 802.11 WAPs.

polygons

Multisided shapes used in 3-D rendering of objects. In computers, video cards draw large numbers of triangles and connect them to form polygons.

pinch

Multitouch gesture that enables you to make an image bigger or smaller.

CSMA/CD (Carrier Sense Multiple Access/Collision Detection)

Networking scheme used by Ethernet devices to transmit data and resend data after detection of data collisions.

imaging process

Seven-step process in laser printing. While it can vary by printer, the steps are typically: processing, charging, exposing, developing, transferring, fusing, and cleaning.

Trojan horse

Program that does something other than what the user who runs the program thinks it will do. Used to disguise malicious code.

rootkit

Program that takes advantage of very low level functionality to gain privileged system access and hide itself from all but the most aggressive anti-malware tools. Can strike operating systems, hypervisors, and even device firmware.

device driver

Program used by the operating system to control communications between the computer and peripherals.

regedit.exe

Program used to edit the Windows Registry.

Cell Tower Analyzer

Program, app, or device to scan and analyze the properties of nearby cellular signals. Can be used to diagnose signal quality issues or identity security threats such as tower spoofing.

Wi-Fi analyzer

Program, app, or device used to scan and analyze the properties of nearby Wi-Fi signals. Can be used to identify dead spots, avoid interference from other networks, or identify security threats such as illegitimate wireless access points, and more.

software token

Programming (usually running on a general computing device such as a smartphone or portable computer) that enables the device to serve as an authentication factor when logging into a secure resource.

Gestures

Specific motions the user performs on a touchscreen, such as pinching or swiping, that have a special meaning to the app being used.

file permission

Specifies what degree of access the system should grant a user or group to a particular file.

folder permission

Specifies what degree of access the system should grant a user or group to a particular folder.

system bus speed

Speed at which the CPU and the rest of the PC operates; set by the system crystal.

ppm (pages per minute)

Speed of a printer.

Pretty Good Privacy (PGP)

Standard for sending and receiving e-mail encrypted to obscure its message from anyone without the key to decrypt it.

form factor

Standard for the physical organization of motherboard components and motherboard size. Most common form factors are ATX, microATX, and Mini-ITX.

RS-232

Standard port recommended by the Electronics Industry Association for serial devices.

dipole antennas

Standard straight-wire antennas that provide the most omnidirectional function.

MSDS (Material Safety Data Sheet)

Standardized form that provides detailed information about potential environmental hazards and proper disposal methods associated with various computing components.

mSATA

Standardized smaller SATA form factor for use in portable devices

Qi

Standardized wireless charging technology.

msinfo32 (System Information tool)

Provides information about hardware resources, components, and the software environment. Also known as System Information.

scripting language

Set of commands, syntax, variables, and format for scripts to be used in a specific computer environment. For example, bash is a scripting language often used in bash shell, which is common on UNIX environments.

maintenance kit

Set of commonly replaced printer components provided by many manufacturers.

code

Set of symbols representing characters or instructions in a computer program.

expansion bus

Set of wires going to the CPU, governed by the expansion bus crystal, directly connected to expansion slots of varying types (PCI, AGP, PCIe, etc.).

boot options

Settings in the system setup program that define which devices the system will attempt to boot from (and in what order).

user profiles

Settings that correspond to a specific user account and may follow users regardless of the computers where they log on. These settings enable the user to have customized environment and security settings.

broadcast domain

group of computers connected by one or more switches; a LAN is almost always one

half-duplex

transmission mode where a device can either send or receive, but not do both at once.

DDR3U

ultra-low-voltage version of DDR3, runs at 1.25 V.

AGP (Accelerated Graphics Port)

32/64-bit expansion slot designed by Intel specifically for video that runs at 66 MHz and yields a throughput of at least 254 Mbps. Later versions (2x, 4x, 8x) give substantially higher throughput

1000BaseT

A Gigabit Ethernet standard using CAT 5e/6 UTP cabling, with a 100-m maximum cable distance and designed to run at 1000 Mbps.

Advanced Encryption Standard (AES)

A block cipher created in the late 1990s that uses a 128-bit block size and a 128-, 192-, or 256-bit key size. Practically uncrackable.

API (Application Programming Interface)

A library of related commands available for programmers to use. OpenGL and DirectX, for example, are two well-known 3-D graphics APIs that make it easier top build 3-D games.

Access Control List (ACL)

A clearly defined list of permissions that specifies what actions an authenticated user may perform on a shared resource.

Audio Editing Workstation

A computer workstation for editing audio needs a fast multicore CPU, lots of RAM, and a large monitor. It also needs large, fast hard drives and a high-quality audio interface, and may make use of specialized input devices for mixing audio.

air filter mask

A mask designed to keep users from inhaling particulate matter, as when cutting drywall.

administrative shares

Administrator tool to give local admins access to hard drives and system root folders.

activity light

An LED on a NIC, hub, or switch that blinks rapidly to show data transfers over the network.

antistatic bag

Bag made of antistatic plastic into which electronics are placed for temporary or long-term storage. Used to protect components from electrostatic discharge.

ALU (Arithmetic Logic Unit)

CPU logic circuits that perform basic arithmetic (add, subtract, multiply and divide).

active PFC (power factor correction)

Circuitry built into PC power supplies to reduce harmonics.

AnandTech (anandtech.com)

Computer hardware, technology, and Internet news and information site.

Administrator Password

Credentials for the system administrator account.

ad hoc mode

Decentralized wireless network mode, otherwise known as peer-to-peer mode, where each wireless node is in meshed contact with every other node.

analog

Device that uses a physical quantity, such as length or voltage, to represent the value of a number, by contrast, digital storage relies on a coding system of numeric units.

10BaseT

Ethernet LAN designed to run on twisted pair cabling. 10BaseT runs at 10 Mbps. The maximum length for the cabling between the NIC and the switch (or hub, repeater, etc.) is 100 meters. It uses baseband signaling. No industry-standard naming convention exists, so sometimes it's written 10BASE-T or 10Base-T.

100BaseT

Ethernet cabling system designed to run at 100 Mbps on twisted pair cabling. It uses baseband signaling. No industry-standard naming convention exists, so sometimes it's written 100BASE-T or 100Base-T.

10 Gigabit Ethernet (10GbE)

Ethernet standard that supports speeds of up to 10 Gbps. Requires CAT 6 or better twisted pair of fiber optic cabling.

Accelerometer

Feature in smartphones and tablets that rotates the screen when the device is physically rotated.

APIPA (Automatic Private IP Addressing)

Feature of Windows that automatically assigns an IP address to the system when the client cannot obtain an IP address automatically.

ADSL (asymmetric digital subscriber line)

Fully digital, dedicated connection to the telephone system that provides average download speeds of 3-15 Mbps and upload speeds of 384 Kbps to 15 Mbps. Asymmetric identifies that upload and download speeds are different, with download usually being significantly faster than upload.

Applet

Generic term for a program in the Windows Control Panel.

administrative tools

Group of Control Panel applets, including Computer Management, Event Viewer, and Reliability and Performance Monitor

Anti-aliasing

In computer imaging, blending effect that smooths sharp contrast between two regions (jagged lines, different colors); reduces jagged edges of text or objects. In voice signal processing, process of removing or smoothing our spurious frequencies from waveforms produced by converting digital signals back to analog.

ASCII (American Standard Code for Information Interchange)

Industry-standard 8-bit characters used to define text characters, consisting of 96 upper- and lower case letters, plus 32 nonprinting control characters, each of which is numbered. These numbers were designed to achieve uniformity among computer devices for printing and the exchange of simple text documents.

Android application package (APK)

Installation software for Android apps

asset tag

Inventory tracking tags (which may be simple barcodes or use wireless networking protocols such as RFID) that help an organization track items such as equipment.

apt-get

Linux command for installing or updating a program using the advanced packaging tool.

administrator group

List of members with complete administrator privileges; complete control over a machine

assertive communication

Means of communication that is not pushy or bossy but is also not soft. Useful in dealing with upset customers as it both defuses their anger and gives them confidence that you know what you're doing.

application manager

Mobile device interface for removing and managing apps running on the device.

airplane mode

Mode for mobile devices that disables all wireless and cellular communicationcom- munication for use on airplanes.

AT (Advanced Technology)

Model name of the second-generation, 80286-based IBM computer. Many aspects of the AT, such as the BIOS, CMOS, and expansion bus, have become de facto standards in the PC industry. The physical organization of the components on the motherboard is called the AT form factor.

active partition

On a hard drive, primary partition that contains an operating system.

40-pin ribbon cable

PATA cable used to attach EIDE devices (such as hard drives) or ATAPI devices (such as optical drives) to a system. (See PATA.)

actively listen

Part of respectful communication involving listening and taking notes without interrupting.

ATX (Advanced Technology Extended)

Popular motherboard form factor that generally replaced the AT form factor.

2-in-1

Portable devices that attempt to serve as both a laptop and a tablet.

ACPI (Advanced Configuration and Power Interface)

Power management specification that far surpasses its predecessor, APM, by providing support for hot-swappable devices and better control of power modes.

3-D printer

Printer that uses a process called additive manufacturing to create an object by adding material to a three-dimensional object, one horizontal layer at a time. (Or) Printer that can print solid objects such as clothing, prosthetics, eyewear, implants, toys, parts, prototypes, and more.

activation (software)

Process of confirming that an installed copy of a Microsoft product (most commonly Windows or Microsoft Office application) is legitimate. Usually done at the end of software installation.

app scanner

Program that scans the app installed on a device to highlight risks posed by apps and what actions they have permission to take.

ARP (Address Resolution Protocol)

Protocol in the TCP/IP suite used with the command-line utility of the same name (arp) to determine the MAC address that corresponds to a particular IP address.

Aspect Ratio

Ratio of width to height of a display. Wide-screen displays such as modern TVs, desktop computer monitors, portable computer displays, and even smartphones commonly use 16:9 or 16:10, but you can find devices with many other aspect ratios.

3 Gbps

SATA drive variety with maximum throughput of 300 MBps.

6 Gbps

SATA drive variety with maximum throughput of 600 MBps.

Access Control

Security concept using physical security, authentication, users and groups, and security policies.

ATAPI (Advanced Technology Attachment Packet Interface)

Series of standards that enables mass storage devices other than hard drives to use the IDE/ATA controllers. Popular with optical drives.

Algorithm

Set of rules for solving a problem in a given number of steps.

address bus

Set of wires leading from the CPU to the memory controller chip (traditionally the Northbridge) that enables the CPU to address RAM. Also used by the CPU for I/O addressing. On current CPUs with built-in memory controllers, the address bus refers to the internal electronic channel from the microprocessor to RAM, along which the addresses of memory storage locations are transmitted. Like a post office box, each memory location has a distinct number or address; the address bus provides the means by which the microprocessor can access every location in memory.

Android

Smartphone and tablet OS created by Google.

antivirus program

Software designed to combat viruses by either seeking out and destroying them or passively guarding against them.

Anti-Malware Program

Software designed to identify and block or remove malware. Typically powered by frequently updated definition files containing the signatures of known malware.

5.1 speaker system

Speaker setup consisting of four satellite speakers plus a center speaker and a subwoofer.

7.1 Speaker System

Speaker setup consisting of six satellite speakers (two front, two side, two rear) plus a center speaker and a subwoofer.

2.1 speaker system

Speaker setup consisting of two stereo speakers combined with a subwoofer.

antistatic wrist strap

Special device worn around the wrist with a grounding connection designed to equalize electrical potential between a technician and an electronic device. Used to prevent electrostatic discharge.

antistatic mat

Special surface on which to lay electronics. These mats come with a grounding connection designed to equalize electrical potential between a workbench and one or more electronic devices. Used to prevent electrostatic discharge.

App history

Tab added to Task Manager in Windows 8 to collect stats such as CPU time and network usage on programs that have run recently.

Applications

Tab in Task Manager that lists the running applications.

ANSI/TIA

The Telecommunication Industry Association (TIA) establishes the UTP categories under the ANSI/TIA 568 specification. The American National Standards Institute (ANSI) accredits TIA standards to ensure compatibility of industry and international standards.

Aero

The Windows 7 desktop environment. Often used as a shorthand for one of its more obvious aesthetic effects: a window transparency feature called Aero Glass.

5G

The fifth generations of cellular technologies. Technologies in this wave are still cutting their teeth, with development just getting underway in 2019.

4G

The fourth generation of cellular data technologies. most popularly implemented as Long Term Evolution (LTE), a wireless data standard with theoretical download speeds of 1 Gbps and upload speeds of 100 Mbps.

110 block

The most common connection used with structured cabling, connecting horizontal cable runs with patch panels.

Attack Vector

The route or methods used by given attack (including malware).

3G

Third generation wireless communication technologies (such as EV-DO, UTMS, HSPA+, and HSDPA) with real-world speeds under 10 Mbps.

address space

Total amount of memory addresses that an address bus can contain.

active matrix

Type of liquid crystal display (LCD) that replaced the passive matrix technology used in most portable computer displays. Also called TFT (thin film transistor).

Adware

Type of malicious program that downloads ads to a user's computer, generating undesirable network traffic.

amperes (amps or A)

Unit of measure for amperage, or electrical current.

administrator account

User account, created when the OS is first installed, that is allowed complete, unfettered access to the system without restriction.

Augmented Reality (AR)

Using some form of hardware (such as a smartphone or an AR headset) to enhance the wearer's experience of the world by adding an interface layer. The interface layer presents information such as the time or navigation instructions and may also support interaction.

attributes

Values in a file that determine the hidden, read-only, system, and archive status of the file.

3-D graphics

Video technology that attempts to create images with the same depth and texture as objects seen in the real world.

Advanced Startup Options menu

Windows 7 menu that can be reached during the boot process that offers advanced OS startup options, such as to boot to Safe Mode or boot into Last Known Good Configuration.

802.11n

Wireless networking standard that can operate in both the 2.4-GHz and 5-GHz bands and uses multiple in/multiple out (MIMO) to achieve a theoretical maximum throughput of 100+ Mbps.

802.11b

Wireless networking standard that operates in the 2.4-GHz band with a theoretical maximum throughput of 11 Mbps.

802.11g

Wireless networking standard that operates in the 2.4-GHz band with a theoretical maximum throughput of 54 Mbps and is backward compatible with 802.11b.

802.11ac

Wireless networking standard that operates in the 5-GHz band and uses multiple in/multiple out (MIMO) and multi-user MIMO (MU-MIMO) to achieve a theoretical maximum throughput of 1+ Gbps.

802.11a

Wireless networking standard that operates in the 5-GHz band with a theoretical maximum throughput of 54 Mbps.

AR headset

a non immersive headset (such as a set of glasses) that places an interface between the wearer and the world.

Apple Pay

mobile payments service and digital wallet app that utilizes Near Field Communication (NFC) to initiate secure payment transactions

Action Center

A one-page aggregation of event messages, warnings, and maintenance messages in Windows 7.

Account Recovery

A process enabling users to regain account access, typically by resetting a lost or forgotten password.

app

A program for a tablet or smartphone. Also, a program written for the Windows 8 Metro interface.

application

A program that enables you to perform a specific task on a computer, such as write a document or play a game.

ATA (AT Attachment)

A series of hard drive standards defining both the older parallel ATA (PATA) and modern serial ATA (SATA) drives.

64-bit processing

A type of processing that can run a compatible 64-bit operating system, such as Windows 7, 8, 8.1, or 10 and 64-bit applications. PCs have a 64-bit-wide address bus, enabling them to use more than 4 GB of RAM.

Accelerated Processing Unit (APU)

AMD product that consolidates the GPU and CPU into a single chip

Advanced Host Controller Interface (AHCI)

An efficient way for motherboards to work with SATA host bus adapters. Using AHCI unlocks some of the advanced features of SATA, such as hot-swapping and native command queuing.

App Store

Apple's mobile software storefront, where you can purchase apps for your smartphone, tablet, or other Apple products

Apps and Features

Area of the Windows 10 Settings App that enables users to add and remove programs and Windows features.

APM (Advanced Power Management)

BIOS routines (developed by Intel in 1992 and upgraded over time) that enable the CPU to turn on and off selected peripherals. In 1996, APM was supplanted by Advanced Configuration and Power Interface (ACPI).

AMD (Advanced Micro Devices)

CPU and chipset manufacturer that competes with Intel. Produces FX, A-Series, Phenom II, Athlon, Sempron, and Opteron CPUs and APUs. Also produces video card processors under its ATI brand.

Apple Filing Protocol (AFP)

Enables sharing between Macs. Also used by macOS Time Machine for backing up macOS over the network. Uses TCP port 548.

ARM

Energy-efficient processor design frequently used in mobile devices.

AC(alternating current)

Type of electricity in which the flow of electrons alternates direction, back and forth, in a circuit. The current delivered through wall plugs.

Single sided RAM

Has chips on only one side as opposed to double-sided RAM.

iwconfig

Linux command for viewing and changing wireless settings.

pwd

Linux command that displays the user's current path.

grep

Linux command to search through text files or command outputs to find specific information or to filter out unneeded information.

chmod

Linux command used to change permissions.

image-level backup

Backing up a complete volume including any OS, boot files, applications, and data it contains.

impersonation

Backing up a complete volume including any OS, boot files, applications, and data it contains.

CAT 5e

Category 5e wire; TIA/EIA standard for UTP wiring that can operate at up to 1 Gbps.

Cat 6

Category 6 wire; TIA/EIA standard for UTP wiring that can operate at up to 10 Gbps.

chown

Linux command used to change the owner and the group to which a file or folder is associated.

fsck

Linux command-line tool that checks for hard drive errors

remnant

Potentially recoverable data on a hard drive that remains despite formatting or deleting.

positional audio

Range of commands for a sound card to place a sound anywhere in 3-D space.

Clock Wire (CLK)

A special wire that, when charged, tells the CPU that another piece of information is waiting to be processed.

punchdown tool

A specialized tool for connecting UTP wires to a punchdown block.

crimper

A specialized tool for connecting twisted pair wires to an RJ-45 connector. Also called a crimping tool.

transfer rate

Rate of data transferred between two devices, especially over the expansion bus.

structured cabling

ANSI/TIA standards that define methods of organizing the cables in a network for ease of repair and replacement.

HTML (Hypertext Markup Language)

ASCII-based, script-like language for creating hypertext documents such as those on the World Wide Web.

Principle of Least Privilege

Accounts should have permission to access only the resources they need and no more.

LBA (logical block addressing)

Addressing scheme that presents storage chunks on a storage device to the OS as a sequence of blocks beginning with LBA0. This saves the OS from having to deal directly with the details of how storage space is arranged on a hard drive or SSD.

USMT (User State Migration Tool)

Advanced application for file and settings transfer of multiple users. Only usable within a Windows Server Active Directory domain.

Point-to-Point Tunneling Protocol (PPTP)

Advanced version of the Point-To-Point Protocol (PPP; used for dial-up Internet) that has improved VPN support.

Power Users group

After Administrator/Administrators, the second most powerful account and group type in Windows. Power users have differing capabilities in different versions of Windows.

URL (Uniform Resource Locator)

An address that defines the location of a resource on the Internet. URLs are used most often in conjunction with HTML and the World Wide Web.

IMAP4 (Internet Message Access Protocol, version 4)

An alternative to POP3 that retrieves e-mail from an e0mail server; IMAP uses TCP port 143.

QR Scanner

An application or device capable of scanning and interpreting QR codes.

BYOD (bring your own device)

An arrangement in some companies' IT departments where employees are permitted to use their own phones or other mobile devices instead of company-issued ones. Also, a feature of some wireless carriers where you can buy an unsubsidized device and use it to get cheaper wireless rates.

DDoS (Distributed Denial of Service)

An attack on a computer or network device in which multiple computers send data and requests to the device in an attempt to overwhelm it so that it cannot perform normal operations.

DoS (Denial of Service)

An attack on a computer resource that prevents it from performing its normal operations, usually by overwhelming it with large numbers of requests in an effort to monopolize its resources.

Phishing

An attack that sends an email or displays a Web announcement that falsely claims to be from a legitimate enterprise in an attempt to trick the user into surrendering private information

Cat 6a

Category 6a wire; augmented CAT 6 UTP wiring that supports 10GbE networks at the full 100-meter distance between a node and a switch.

end-user acceptance

Change management step that entails educating and training users about what has changed and how to use any new systems, devices, or features.

optimization

Changes made to a system to improve its performance.

soft power

Characteristic of ATX motherboards, which can use software to turn the PC on and off. The physical manifestation of soft power is the power switch. Instead of the thick power cord used in AT systems, an ATX power switch is little more than a pair of small wires leading to the motherboard.

rapid elasticity

Characteristic of cloud computing that enables cloud consumers to add or remove capacity quickly. Because cloud servers are powered by virtual machines, customers can start or shut down new instances of VMs or move the VMs to more powerful hardware.

primary corona wire

Charges the photosensitive particles on the imaging drum. Replaced by the primary charge roller in newer laser printers.

Super I/O chip

Chip specially designed to control low-speed, legacy devices such as the keyboard, mouse, and serial and parallel ports.

MCC (memory controller chip)

Chip that handles memory requests from the CPU. Although once a special chip, it has been integrated into the chipset or CPU on modern computers.

Hierarchical File System Plus (HFS+)

Classic file system used by older Macs. Still required for Time Machine devices. Replaced in new Macs and existing compatible systems with Apple File System (AFS).

BIOS (basic input/output services) (basic input/output system)

Classically, software routines burned onto the system ROM of a PC. More commonly seen as firmware that directly controls a particular piece of hardware. This firmware handles startup operations and low-level control of hardware such as disk drives, the keyboard, and monitor.

gain

Ratio of increase of radio frequency output provided by an antenna, measured in decibels (dB).

plastic filament

Raw material that a typical 3-D printer melts and then extrudes to create physical pieces and parts.

CD-ROM (compact disc read-only memory)

Read-only compact storage disc for audio or video data. CD-ROMs are read by using CD-ROM drives and optical drives with backward compatibility, such as DVD and Blu-ray Disc drives.

mirroring

Reading and writing data at the same time to two drives for fault tolerance purposes. Considered RAID level 1. Also called drive mirroring.

incident report

Record of the details of an accident, including what happened and where it happened.

document findings, actions, and outcomes

Recording each troubleshooting job: what the problem was, how it was fixed, and other helpful information. (Step 6 of 6 in the CompTIA troubleshooting theory.)

dual boot

Refers to a computer with two operating systems installed, enabling users to choose which operating system to load on boot. Can also refer to kicking a device a second time just in case the first time didn't work.

client/server

Relationship in which client software obtains services from a server on behalf of a person.

remediation

Repairing damage caused by a virus.

UDF (universal data format)

Replaced the ISO-9660 formats, enabling any operating system and optical drive to read UDF formatted disks.

Primary charge roller

Replaces the primary corona wire in newer laser printers. The roller, which is very close to the photosensitive drum, is given a very high charge, forming an electric field (corona) and passing a charge to the photosensitive drum.

hot-swapping

Replacing a bad drive in a RAID array without needing to reboot or power down

emergency repair disk (ERD)

Saves critical boot files and partition information and is the main tool for fixing boot problems in older versions of Windows. Newer versions of Windows call this a system repair disc (Windows Vista/7) or recovery drive (Windows 8/8.1 and 10).

Control Panel

Collection of Windows applets, or small programs, that can be used to configure various pieces of hardware and software in a system.

profile (network)

Collection of information necessary to automatically connect to a network, stored by network's SSID. Enables mobile and portable devices to easily use many networks.

VoIP (Voice over Internet Protocol)

Collection of protocols that makes voice calls over a data network possible.

service pack

Collection of software patches released at one time by a software manufacturer.

network

Collection of two or more computers interconnected by telephone lines, coaxial cables, satellite links, radio, and/or some other communication technique. Group of computers that are connected and that communicate with one another for a common purpose.

group

Collection of user accounts that share the same access capabilities.

sRGB

Color space standard that corresponds to Standard Dynamic Range (SDR).

edge LED backlighting

Columns or rows of LEDs placed along the sides or top of a display panel to illuminate the display.

Classless Inter-Domain Routing (CIDR)

Current system for creating and notating subnets, it replaced the older, less flexible three class system

1.5 Gbps

SATA drive variety with maximum throughput of 150 MBps.

SDRAM (synchronous DRAM)

DRAM that is synchronous, or tied to the system clock. This type of RAM is used in all modern systems.

DVD-ROM

DVD equivalent of the standard CD-ROM.

DVD-Video

DVD format used exclusively to store digital video; capable of storing over two hours of high-quality video on a single DVD.

spear phishing

Dangerous targeted phishing attack on a group or individual that carefully uses details from the target's life to increase the odds they'll take the bait.

resources

Data and services such as files, folder, drives, printers, connections, and so on.

degaussing

Data destruction procedure used to reduce or remove the electromagnetic fields that store data on magnetic hard drives.

SSD (solid state drive)

Data storage device that uses flash memory to store data.

NVMe (Non-Volatile Memory Express)

SSD tech that supports a communication between the operating system and the SSD directly through a PCIe bus lane, reducing latency and taking full advantage of the speeds high-end SSDs. NVMe SSDs come in a couple of formats, such as an add-on expansion card and a 2.5 inch drive, like the SATA drives for portables. NVMe drives are a lot more expensive currently than other SSDs, but offer much higher speeds. NVMe drives use SATAe.

program/programming

Series of binary electronic commands sent to a CPU to get work done.

OS (Operating System)

Series of programs and code that creates an interface so users can interact with a system's hardware; for example, Windows, macOS, and Linux.

print server

Server, computer, or standalone network device that shares access to a printer over a network.

TCP/IP Services

Services such as HTTP or SSH that run atop TCP/IP.

encrypted

Data that has been passed through an encryption algorithm, rendering it unreadable without the decryption keys.

HDD (Hard Disk Drive)

Data-recording system using solid disks of magnetic material turning at high speeds to store and retrieve programs and data in a computer.

hardware token

Dedicated device that contains information used as an authentication factor when logging on to a secure site.

bash

Default command shell on macOS and most Linux distributions.

hardware protocol

Defines many aspects of a network, from the packet type to the cabling and connectors used.

AUP (Acceptable Use Policy)

Defines what action employees may or may not preform on company equipment, including computers, phones, printers, and even the network itself. This policy defines the handling of passwords, e-mail, and many other issues.

scope of the change

Defines who and what the change will affect. May include an inventory of systems to change, people involved, time required, and estimated cost.

pixels per inch (PPI)

Density of pixels on a display or a light sensor; the higher the density, the greater the resolution.

TKIP (Temporal Key Integrity Protocol)

Deprecated encryption standard that provided a new encryption key for every sent packet.

x86

Describes 32-bit operating systems and software.

x64

Describes 64-bit operating systems and software.

pin 1

Designator used to ensure proper alignment of floppy drive and hard drive connectors.

router

Device connecting separate networks; forwards a packet from one network to another based on the network address for the protocol being used. For example, an IP router looks only at the IP network number. Routers operate at Layer 3 (Network) of the OSI seven layer model.

portable battery recharger

Device containing a rechargeable battery that can be used to charge other devices, typically over USB, when no outlets are available.

digitizer (peripheral)

Device enabling users to paint, ink, pencil, or otherwise draw with a computer. Also known as a pen tablet.

projector

Device for projecting video images from PCs or other video sources, usually for audience presentations. Available in front- and rearview displays.

TDR (Time-Domain Reflectometer)

Device for testing network cabling by measuring impedance (which is similar to resistance); any impedance means a bad cycle.

cable tester

Device for verifying that a network can carry a signal from one end to the other, and that all wires within the connector are in their correct position.

POST card

Device installed into a motherboard expansion slot that assists in trouble- shooting boot problems by providing a two-digit code indicating the stop of the boot process where the problem is occurring.

memory

Device or medium for temporary storage of programs and data during program execution. Synonymous with storage, although it most frequently refers to the internal storage of a computer that can be directly addressed by operating instructions. A computer's temporary storage capacity is measured in kilobytes (KB), megabytes (MB), or gigabytes (GB) of RAM (random access memory). Long term data storage on hard drives and solid state drives is also measured in megabytes, gigabytes and terabytes.

credit card reader

Device that can be attached to mobile phones and tablets to take credit card payments

gyroscope

Device that can detect the position of the tablet or phone in 3-D space.

WAP (Wireless Access Point)

Device that centrally connects wireless network nodes.

Wireless repeater/extender

Devices that receive and rebroadcast a Wi-Fi signal to increase coverage.

PCI-X (PCI Extended)

Enhanced version of PCI, 64 bits wide. Typically seen in servers and high-end systems.

Full Device Encryption

Enhances mobile device security by encrypting the device's internal storage.

System on a Chip (SoC)

Single silicon die containing a CPU, GPU, and other important support logic.

power conditioning

Ensuring and adjusting incoming AC wall power to as close to standard as possible. Most UPS devices provide power conditioning.

Mini-PCIe

Specialized form of PCIe designed for use in laptops.

GPU (graphics processing unit)

Specialized processor that helps the CPU by taking over all of the 3-D rendering duties.

Video card

Expansion card on the motherboard that provides a connection for the monitor

Dolby Digital

Technology for sound reductions and channeling methods used for digital audio.

compression

The process of reducing the space required to store data by efficiently encoding the content.

cron

Tool used by many Linux distributions for automatically running tasks based on a schedule.

cable internet

Fast Internet connection from a cable TV provider via RG-6 or RG-59

SAS (serial-attached SCSI)

Fast, robust storage interface based on the SCSI command set. Also supports SATA devices. Used mainly in servers and storage arrays.

Emergency notification

Feature built into smartphones enabling them to receive messages from emergency broadcast systems, such as the Emergency Alert System (EAS) in the United States.

screen lock

Mobile device feature that locks the screen until some form of authentication challenge is passed.

change board

a group of representatives from around the organization who review and approve change proposals.

broadband

a high-capacity transmission technique using a wide range of frequencies, which enables a large number of messages to be communicated simultaneously.

MPEG-4

Moving Pictures Experts Group standard of video and audio compression offering improved compression over MPEG-2.

MPEG-2

Moving Pictures Experts Group standard of video and audio compression offering resolutions up to 1280 × 720 at 60 frames per second.

migration

Moving users from one operating system or hard drive to another.

smartphone

A cell phone enhanced to do things formerly reserved for fully grown computers, such as Web browsing, document viewing, and media consumption.

wildcard

A character used to find words or phrases that contain specific letters or combinations of letters.(usually an asterisk or question mark like *.docx)

triple-channel architecture

A chipset feature similar to dual-channel RAM, but requiring three matched sticks instead of two.

Domain Controller

A computer running Windows Server with Active Directory installed; maintains a database of user and computer accounts as well as network access policies in a Windows domain

Web server

A computer that stores and shares the files that make up Web sites.

share-level security

A security system in which each resource has a password assigned to it; access to the resource is based on knowing the password.

Yagi

Multi-element antennas that increase signal gain in a specific direction. Resembles older television antennas, but smaller.

cellular card

A cellular modem on an expansion card designed for older laptop expansion slots. Current add-on cellular modems are typically attached via USB (and called USB modems by cellular service providers).

microprocessor

"Brain" of a computer. Primary computer chip that determines relative speed and capabilities of the computer. Also called CPU.

Mac

(Also Macintosh.) Common name for Apple Computers' flagship operating system; runs on Intel-based hardware. CompTIA refers to the operating system as Mac OS X. Apple calls the current operating system OS X, dropping the Mac altogether.

imaging drum

- Aluminum cylinder coated with particles of photosensitive compounds. When light hits these particles, whatever electrical charge they may have "drains" out through the grounded cylinder. After the particles are selectively charged by the laser, they attract the toner particles, forming the image that will be transferred. Often built into the toner cartridge. Also known as photosensitive drum.

SATA power connector

15-pin, L-shaped connector used by SATA devices that support the hot-swappable feature.

Unicode

16-bit code that covers every character of the most common languages, plus several thousand symbols.

DIMM (dual inline memory module)

32- or 64-bit type of DRAM packaging with the distinction that each side of each tab inserted into the system performs a separate function. DIMMs come in a variety of sizes, with 184-, 240-, and 288-pin being the most common on desktop computers.

Test the theory to determine cause

3rd step in the troubleshooting process.

Standard Dynamic Range (SDR)

8-bit color standard that defines 256 colors or light intensities.

VGA connector

A 15-pin, three-row, D-type VGA monitor connector. Goes by many other names, such as D-shell, D-subminiature connector, DB-15, DE-15, and HD15. The oldest and least-capable monitor connection type.

prompt

A character or message provided by an operating system or program to indicate that it is ready to accept input.

multiple Desktops

A GUI feature that enables a computer to have more than one Desktop, each with its own icons and background. Mac OS X supports multiple Desktops with Spaces. Most Linux distros use multiple Desktops, often called workspaces. Microsoft introduced the feature with Windows 10.

swollen battery

A Li-On battery that ahs begun to swell as it fails, often due to manufacturing defects, heat or overcharging. May also deform the device containing it. it is an explosion and fire risk if it ruptures, so dispose of it quickly and safely.

exFAT

A Microsoft-proprietary file system that breaks the 4-GB file-size barrier, supporting files up to 16 exabytes (EB) and a theoretical partition limit of 64 zettabytes (ZB). Envisioned for use with flash media devices with a capacity exceeding 2 TB.

RAID 0 + 1

A RAID 0 configuration created by combining two RAID 1s. Provides both speed and redundancy, but requires at least four disks.

Secure Boot

A UEFI feature that prevents a system from booting up with drivers or an OS that are not digitally signed and trusted by the motherboard or computer manufacturer.

Credential Manager

A Windows Control Panel applet which manages saved logon information for Web sites, applications, and networks.

bootrec

A Windows Recovery Environment troubleshooting and repair tool that repairs the master boot record, boot sector, or BCD store. It replaces the fixboot and fixmbr Recovery Console commands used in Windows XP and earlier operating systems.

Windows XP mode

A Windows XP virtual machine that ships with Professional, Enterprise, and Ultimate editions of Windows 7 to enable users to run programs that don't work on Windows 7.

HomeGroup

A Windows feature that connects a group of computers using a common password—no special usernames required. Each computer can be a member of only one homegroup at a time. Homegroups enable simple sharing of documents and printers between computers. Available in Windows 7, 8, 8.1 and 10.

offline files

A Windows feature that enables client computers to maintain copies of server files on their local drives. If the computer's connection to the network is severed or interrupted, the client can continue to work with the local copies until network service is restored, at which time the client synchronizes its data with the data on the server.

AutoPlay

A Windows feature that opens a dialog box when removable media is inserted into the computer, providing options based on what Windows finds on the drive, including the Autorun application.

Backup and Restore

A Windows utility that allows the user to create a duplicate copy of all the data on the hard drive and copy it to another storage device.

Task Manager

A Windows utility that shows programs currently running and permits you to exit nonresponsive programs when you click End Task.

Dock

A bar at the bottom of the Mac OS X desktop where application icons can be placed for easy access.

stranded core

A cable that uses a bundle of tiny wire strands to transmit signals. Stranded core is not quite as good a conductor as solid core, but it will stand up to substantial handling without breaking.

solid core

A cable that uses a single solid (not hollow or stranded) wire to transmit signals.

protective cover

A case or sleeve that protects a mobile device from physical damage.

profile (MDM)

A collection of mobile device management (MDM) configuration and security settings that an administrator has created in order to apply those settings to particular categories of users or devices.

hybrid cloud

A combination of public and private clouds.

Terminal

A command-line tool available in macOS and various Linux distros.

DISM (Deployment Image Servicing and Management)

A command-line tool bundled with Windows 10 to support image deployment. Also known as dism.exe.

bcedit

A command-line tool that enables you to view the BCD store, which lists the Windows boot options.

ping

A command-line utility that can be used to test IP communications between the computer running the utility and a remote target.

remote network installation

A common method of OS installation where the source files are placed in a shared directory on a network server. Then, whenever a tech needs to install a new OS, he or she can boot the computer, connect to the source location on the network, and start the installation from there.

ISP (internet service provider)

A company that provides customers access to the Internet.

virtual machine (VM)

A complete environment for a guest operating system to function as though that operating system were installed on its own computer.

fully qualified domain name (FQDN)

A complete, bottom-to-top label of a DNS host going from the specific host to the top-level domain that holds it and all of the intervening domain layers, each layer being separated by a dot. FQDNs are entered into browser bars and other utilities in formats like mail.totalseminars.com

backlight

A component used in LCDs to illuminate an image. In older LCDs this was a CCFL; current LCDs use LEDs.

transfer belt

A component used in some color laser printers. Colors are applied to the belt and then applied to the paper.

Home Server PC

A computer built to store files on a small office/home office (SOHO) network.

video editing workstation

A computer workstation for editing video. Combines the hardware requirements of graphics and audio editing workstations. Typically makes use of two or more high-quality color calibrated monitors for both editing and viewing video at native resolution. The high-speed, high-capacity storage required to edit enormous video files is commonly provided by RAID arrays.

Graphics Workstation

A computer workstation for graphics design that requires a fast, multi-core CPU, maximum RAM, and serious storage space to work with a massive graphics files. It also needs a high quality graphics card and monitor.

virtualization workstation

A computer workstation for simultaneous work in multiple virtual machines requires enough power for the host OS, plus any virtual machines, including their operating systems and software. In practice, this means powerful CPU's with many cores and maximum RAM

bit

A contraction of "Binary Digit". A bit is the single unit of information in a computer, typically represented as a 0 or 1.

frame

A data unit transferred across a network. Frames consist of several parts, such as the sending and receiving MAC addresses, the data being sent, and the frame check sequence.

risk analysis

A detailed assessment of any problems that could result from a change.

Network Attached Storage (NAS)

A device that attaches to a network for the sole purpose of storing and sharing files

bridge

A device that connects dissimilar network technologies that transmit the same signal.

inverter

A device that converts DC current to AC. An inverter is required in a laptop to provide the AC current required by the display.

switch

A device that filters and forwards traffic based on some criteria. A bridge and a router are both examples of switches.

battery charger

A device used to put energy into a secondary cell or rechargeable battery by forcing an electric current through it.

installation media

A disc (typically a CD-ROM or DVD) or drive (such as a USB flash drive) that holds all the necessary device drivers.

chain of custody

A documented history of who has been in possession of a system.

signed driver

A driver designed specifically to work with Windows that has been tested and certified by Microsoft to work stably with Windows.

ITX

A family of motherboard form factors. Mini-ITX is the largest and the most popular of the ITX form factors but is still quite small.

SuperSpeed USB

A fast form of USB, with speeds up to 5 Gbps. Also called USB 3.0.

data roaming

A feature of cellular data systems that enables the signal to jump from cell tower to cell tower and from your provider to another provider without obvious notice.

Mission Control

A feature of macOS that enables switching between open applications, windows, and more.

AutoRun

A feature of the operating system, AutoRun automatically follows the instructions in a special file called autorun.inf when it is found on new media. This can be a security risk and should be disabled.

CIFS (Common Internet File System)

A file access protocol and the cross-platform version of SMB used between Windows, Linux, Mac OS, and other operating systems. Also called SMB2.

hidden attribute

A file attribute that is given to a file to indicate it should not be visible in Windows Explorer unless View settings override the attribute and allow the file to be shown.

toner (printing)

A fine powder made up of plastic particles bonded to pigment particles, used to create the text and images on a page printed with a laser printer.

subfolder

A folder stored within another folder.

MDM (mobile device management)

A formalized structure that enables an organization to account for all the different types of devices used to process, store, transmit, and receive organizational data.

diskpart

A fully functioning command-line partitioning tool.

Personal Computer (PC)

A general computing device that runs Microsoft Windows and can be used for various tasks.

hybrid hard drive (HHD)

A hard drive that incorporates flash technology in its design to speed up the boot process; a compromise between the speed and power efficiency of SSDs and the capacity of HHDs.

Trusted Platform Module (TPM)

A hardware platform for the acceleration of cryptographic functions and the secure storage of associated information. BitLocker. for example, requires a TPM chip on the motherboard to validate on boot that the computer has not changed.

Trusted Root CA

A highly respected certificate authority (CA) that has been placed on the lists of trusted authorities built into Web browsers.

HTPC

A home theater PC designed to attach to a TV or projector for movie and TV viewing.

star bus topology

A hybrid network topology where the computers all connect to a central bus - a switch - and have a layout resembling a star.

CMOS clear

A jumper on the motherboard that, when set, will revert CMOS settings to the factory defaults.

single-factor authentication

A less secure authentication process using only one of the authentication factors.

self grounding

A less than ideal method for ridding yourself of static electricity by touching a metal object such as a computer case.

drive letter

A letter designating a specific drive or partition.

DMZ (demilitarized zone)

A lightly protected or unprotected subnet network positioned between an outer firewall and an organization's highly protected internal network. DMZs are used mainly to host public address servers (such as Web servers).

profile (color)

A list of settings that a calibration device creates when calibrating monitors and printers.

PRL (Preferred Roaming List)

A list that is occasionally and automatically updated to a phone's firmware by the carrier so that the phone will be configured with a particular carrier's networks and frequencies, in a priority order, that it should search for when it can't locate its home carrier network.

network topology diagram

A map of how everything in an organization's network (including switches, routers, WAPs, services, and workstations) connects. May indicate connection types, speed, technologies, and so on.

NAT (Network Address Translation)

A means of translating a system's IP address into another IP address before sending it out to a larger network. NAT manifests itself by a NAT program that runs on a system or a router. A network using NAT provides the systems on the network with private IP addresses. The system running the NAT software has two interfaces: one connected to the network and the other connected to the larger network. The NAT program takes packets from the client systems bound for the larger network and translates their internal private IP addresses to its own public IP address, enabling many systems to share a single IP address.

equipment rack

A metal structure used in equipment rooms to secure network hardware devices and patch panels. Most racks are 19" wide. Devices designed to fit in such a rack use a height measurement called units, or simply U.

network connection

A method for connecting two or more computers together.

liquid cooling

A method of cooling a PC that works by running some liquid—usually water—through a metal block that sits on top of the CPU, absorbing heat. The liquid gets heated by the block, runs out of the block and into something that cools the liquid, and is then pumped through the block again.

tablet

A mobile device consisting of a large touchscreen, enabling the user to browse the Web, view media, and even play games.

mobile hotspot

A mobile device that broadcasts a small Wi-Fi network to share its mobile data network connection with nearby Wi-Fi devices. Often these are standalone devices, though many cellular phones and data-connected tablets can be set up to act as hotspots.

cloud computing

A model for enabling ubiquitous, convenient, on-demand network access to a shared pool of configurable computing resources that can be rapidly provisioned and released with minimal management effort or service provider interaction

ransomware

A nasty form of malware that encrypts data or drives on the infected system and demands payment, often within a limited timeframe, in exchange for the keys to decrypt the data.

overloaded network

A network that, often due to a large public event, emergency, or network equipment failure, is unable to keep up with user demand. Users may have good signal quality but be unable to access data, text, or voice services.

hybrid (networking)

A network topology that combines features from multiple other topologies, such as the star bus topology.

broadcast

A network transmission addressed for every node on the network.

virtual switch

A non-physical version of a hardware switch, made by a hypervisor to network virtual machines.

startup repair

A one-stop, do-it-all troubleshooting option that performs a number of boot repairs automatically.

patch panel

A panel containing a row of female connectors (ports) that terminate the horizontal cabling in the equipment room. Patch panels facilitate cabling organization and provide protection to horizontal cabling.

Thermal Paste

A paste that is used to connect a heat sink to a CPU to provide a liquid thermally conductive compound gel that fills any gaps between the CPU and the heat sink to permit a more efficient transference of heat from the processor to the heat sink.

multi-rail

A power supply configuration where the current is split into multiple pathways, each with a maximum capacity and its own Over Current Protection circuitry. CompTIA calls two-rail versions of this technology "dual rail."

hibernate

A power-management mode that saves the current state of the current system to the computer's hard drive.

network technology

A practical application of a topology and other critical standards to provide a method to get data from one computer to another on a network. It defines many aspects of a network, from the topology, to the frame type, to the cabling and connectors used.

inventory management

A process for protecting devices and equipment by tagging them with barcodes or asset tags, and keeping track of these tagged devices.

disk initialization

A process that places special information on every hard drive installed in a Windows system.

service

A process that runs in the background of a PC but displays no icons anywhere. You can view a list of services in the Windows Task Manager. Also, a program stored in a ROM chip.

Disk Defragmenter

A program that maintains performance by rearranging chunks of data on a storage device to ensure chunks that compromise a file are stored contiguously. Renamed to Optimize Drives in Windows 8 and up.

command

A request, typed from a terminal or embedded in a file, to perform an operation or to execute a particular program.

network documentation

A road map to an organization's network configuration and topology for techs who need to change or repair the network.

barcode

A scannable, read-only binary code often used to mark items for inventory tracking.

VESA mount

A screen or display bracket that follows the industry standard - established by the Video Electronics Standards Association (VESA) - which specifies size, location, and type of mounting points.

proprietary crash screen

A screen, differing between operating systems, that indicates an NMI.

gaming PC

Multicore processor High end video/Specialized GPU High Definition sound card High end cooling

SNMP (Simple Network Management Protocol)

A set of standards for communication with devices connected to a TCP/IP network. Examples of these devices include routers, hubs, and switches. Uses port 161

MMC (Microsoft Management Console)

A shell program in Windows that holds individual utilities called snap-ins, designed for administration and troubleshooting. The MMC enables an administrator to customize management tools by picking and choosing from a list of snap-ins. Available snap-ins include Device Manager, Local Users and Groups, and Computer Management.

workgroup

A simple, decentralized network that Windows PCs are configured to use by default.

run

A single piece of installed horizontal cabling.

mantrap

A small space having two sets of interlocking doors; the first set of doors must close before the second set opens. Typically authentication is required for each door, often using different factors. For example, a smart card may open the first door and a personal identification number entered on a number pad opens the second.

mobile device

A small, lightweight, power-conserving, computing device that is capable of wireless access.

restore point

A snapshot of a computer's configuration at a specific point in time, created by the System Restore utility and used to restore a malfunctioning system.

RAID 5 volume (dynamic disks)

A software based RAID 5 volume made up of three or more dynamic disks with equal-sized unallocated space. Created with Windows Disk Management.

WinRE (Windows Recovery Environment)

A special set of tools in the Windows setup that enables you to access troubleshooting and repair features.

hash

A special value computed from some other value using an irreversible computation. Has many uses in computing, and plays a key role in modern authentication systems. Instead of saving user passwords directly in a database (which would make them a huge target for attackers), well-designed authentication systems compute and save only a (salted) hash of each password. When the user attempts to log in, the system hashes the provided password to see if it matches the saved hash.

heat sink

A specially designed piece of metal that draws heat away from chips, such as the CPU. Heat sinks typically have flared fins, allowing more air through.

DNS domain

A specific branch of the DNS name space. Top-level DNS domains include .com, .gov, and .edu.

distribution (distro)

A specific variant of Linux.

Spinning Pinwheel of Death (SPoD)

A spinning rainbow wheel that serves as the macOS indicator that an application isn't responding and may be busy or frozen.

crossover cable

A standard UTP cable with one RJ-45 connector using the T568A standard and the other using T568B standard. This reserves the signal between sending and receiving wires and thus stimulates the connection to a switch.

Wi-Fi Protected Setup (WPS)

A standard included on many WAPs and clients to make secure connections easier to configure. WPS should be turned off, however, because it has a significant security flaw.

PCI DSS (Payment Card Industry Data Security Standard)

A standard that sets common rules for systems that accept, process, transmit, or store credit/debit card payments. Often referred to as just PCI.

control construct

A statement or unit within a program that is used to alter the default order in which program statements are executed.

DFS (Distributed File System)

A storage environment where shared files are accessed from storage devices within multiple servers, clients, and peer hosts.

convertible

A subset of 2-in-1 portables that use a hinge or latch mechanism to convert between laptop and tablet modes.

thin client

A system designed to handle only very basic applications with an absolute minimum amount of hardware required by the operating system. Meets minimum requirements for selected OS.

Telnet

A terminal emulation protocol that allows users at one site to simulate a session on a remote host.

File Explorer

A tool in Windows 8/8.1/10 that enables users to browse files and folders.

virtual desktop

A traditional desktop OS installed in a VM. A local system could run its own VM containing a virtual desktop, or just connect to a virtual desktop running on a remote server.

Automatic Document Feeder (ADF)

A tray (usually on top) of a scanner or multifunction device that holds a document and enables that device to grab and scan each page automatically for easier scanning, copying, or faxing of long documents.

Certificate Authority (CA)

A trusted third-party agency that is responsible for issuing digital certificates.

DB-9

A two-row DB connector (male) used to connect the computer's serial port to a serial-communication device such as a modem or a console port on a managed switch.

unattended installation

A type of OS installation where special scripts perform all the OS setup duties without human intervention.

gamepad

A type of game controller that usually consists of one or more thumbsticks, a directional pad, multiple face buttons, and two or more triggers.

joystick

A type of game controller. Commonly used for flight-simulator games.

mirror set

A type of mirrored volume created with RAID 1. (See also mirroring.)

dictionary attack

A type of password attack that automates password guessing by comparing encrypted passwords against a predetermined list of possible password values.

Guests group

A type of user group in Windows. User accounts that belong to this group have limited rights to the system and are given a temporary profile that is deleted after the user logs off.

IMSI (International Mobile Subscriber Identity)

A unique number that represents the actual user associated with a particular SIM card. The IMSI is usually available from the carrier, to ensure that stolen phones are not misused. The IMSI number can be used to unlock a phone as well

decibel

A unit used to compare the loudness of different sounds.

profile (user)

A user profile describes a Windows user account's customized environment, including Desktop preferences, color schemes, shortcuts, and so on.

System Restore

A utility in Windows that restores system settings to a specific previous date when everything was working properly.

virus

A virus is a program that has two jobs: to replicate and to activate. Replication means it copies itself. Activation is when a virus damages a system or data. A virus can't self-replicate across networks; it needs human action to spread other drives.

smart watch

A watch incorporating features and communicating with a mobile device.

change management

A well-defined process composed of many planning and execution steps that enables organizations to change their IT infrastructure in a safe. cost-effective manner.

integer

A whole number. Integers and floating point numbers are handled differently in programs and by CPUs.

WAN (Wide Area Network)

A widespread group of computers connected using long-distance technologies.

wait state

Occurs when the CPU has to wait for RAM to provide code. Also known as pipeline stall.

Establish a plan of action to resolve the problem and implement the solution

After establishing and testing a theory about a particular problem, techs solve the problem. (step 4 of 6 in the CompTIA troubleshooting methodology).

establish a theory of probable cause (question the obvious)

After identifying a problem, techs question the obvious to determine what might be the source of the problem. (step 2 of 6 in the CompTIA troubleshooting methodology)

EULA (End User License Agreement)

Agreement that accompanies a piece of software, to which the user must agree before using the software. Outlines the terms of use for the software and also lists any actions on the part of the user that violate the agreement.

protocol

Agreement that governs the procedures used to exchange information between cooperating entities. Usually includes how much information is to be sent, how often it is to be sent, how to recover from transmission errors, and who is to receive the information.

instruction set

All of the machine-language commands that a particular CPU is designed to understand.

checkpoint

Also known as a snapshot. Saves changes to a virtual machine's state. Checkpoints are great for performing maintenance with a safety net, but they aren't a complete backup, and many snapshots can slow a VM down. Get rid of them when the danger has passed.

option ROM

Alternative way of telling the system how to talk to a piece of hardware. Option ROM stores BIOS for the card in a chip on the card itself

latency

Amount of delay before a device may respond to a request; most commonly used in reference to RAM.

current

Amount of electrons moving past a certain point on a wire, measured in units called amperes.

Impedance

Amount of resistance to an electrical signal on a wire. Relative measure of the amount of data a cable can handle.

Lightning

An 8-pin connector, proprietary to Apple, that can be inserted without regard to orientation. Used to connect mobile devices to a power or data source.

launcher

An Android app that serves as the device's desktop, often with more extensive customization features than launchers provided by Google or the device maker.

link light

An LED on NICs, hubs, and switches that lights up to show good connection between the devices.

headphones

An audio, output device worn on the head.

Kerberos

An authentication system developed by the Massachusetts Institute of Technology (MIT) to enable multiple brands of servers to verify the identity of networked users.

SIMM (single inline memory module)

An early DRAM package format that came in two common sizes: 30 pin and 72 pin.

CRC (Cyclic Redundancy Check)

An error detection method that can be applied to blocks of data, rather than individual words. Both the sender and receiver calculate EDC; if they match, the data is assumed to be valid.

bug

An error in a program that prevents the program from running as expected.

microphone

An input device for recording audio.

game controller

An input device used to play computerized games; examples include joysticks and game pads.

Command Line Interface (CLI)

An interface that accepts text commands at a prompt, usually for immediate execution with immediate display of output.

GUI (Graphical User Interface)

An interface that allows users to interact by pointing and clicking rather than by using text commands.

Thunderbolt

An open standards connector interface that is primarily used to connect peripherals to devices, including mobile devices, if they have a corresponding port.

guest

An operating system running inside a virtual machine.

camera

An optical instrument that uses lenses to focus light, and film to record an image of an object.

line of sight

An unobstructed view between two devices. Required for IR communications.

comment

Annotation text included in scripts, programs, and configuration files.

RFI (radio frequency interference)

Another form of electrical interference caused by radio-wave emitting devices, such as cell phones, wireless network cards, and microwave ovens.

directory

Another name for a folder

SATA 3.2

Another term for SATAe.

peripheral

Any device or piece of equipment that is attached to and used by a computer, such as a monitor, tape drive, printer, modem, speakers, etc..

full-duplex

Any device that can send and receive data simultaneously.

system fan

Any fan controlled by the motherboard but not directly attached to the CPU.

hot-swappable

Any hardware that may be attached to or removed from a PC without interrupting the PC's normal processing.

resistor

Any material or device that impedes the flow of electrons. Antistatic wrist straps and mats use tiny resistors to prevent a static charge from racing through the device.

FRU (field replaceable unit)

Any part of a PC that is considered to be replaceable "in the field," i.e., a customer location. There is no official list of FRUs—it is usually a matter of policy by the repair center.

Bootable Disk

Any storage device with a self-starting operating system.

removeable media

Any storage on a computer that can be easily removed. For example, optical discs, flash drives, or memory cards.

unauthorized access

Anytime a person accesses resources in an unauthorized way. This access may or may not be malicious.

iCloud

Apple cloud-based storage. iCloud enables a user to back up all iPhone or iPad data, and makes that data accessible from anywhere. This includes any media purchased through iTunes and calendars, contacts, reminders, and so forth.

BootCamp

Apple tool used to install and boot to versions of Windows on a macOS computer.

User Accounts applet

Applet in Control Panel that enables you to make changes to current accounts (local or global), and gives you access to the Settings charm (or app in Windows 10) when you opt to add a new account.

disk quota

Application allowing network administrators to limit hard drive space usage.

Intrusion Prevention System (IPS)

Application similar to an intrusion detection system (IDS), except that it sits directly in the flow of network traffic. This enables it to stop ongoing attacks itself, but may also slow down the network and be a single point of failure.

Intrusion Detection System (IDS)

Application that inspects packets, looking for active intrusions. Functions inside the network, looking for threats a firewall might miss, such as viruses, illegal logon attempts, and other well-known attacks. May also discover threats from inside the network, such as a vulnerability scanner run by a rogue employee.

print spooler

Area of memory that queues up print jobs that the printer will handle sequentially.

telecommunications room

Area where all the cabling from individual computers in a network converges

queue

Area where objects wait their turn to be processed. Example: the printer queue, where print jobs wait until it is their turn to be printed.

LGA (Land Grid Array)

Arrangement of a large number of pins extending from the CPU socket to corresponding contact points on the bottom of the CPU.

PGA (pin grid array)

Arrangement of a large number of pins extending from the bottom of the CPU package. There are many variations on PGA.

zero-day attack

Attack targeting a previously unknown bug or vulnerability that software or hardware developers have had zero days to fix.

Man-in-the-Middle (MITM)

Attacker serves as an intermediary between the two systems, enabling the attacker to observe, redirect, or even alter messages pausing in either direction.

CD quality

Audio quality that has a sample rate of 44.4 KHz and a bit rate of 128 bits.

CAPTCHA (Completely Automated Public Turing Test to Tell Computers and Humans Apart)

Authentication challenge using images, videos, sounds, or other media to be identified by a user. Computers have a much more difficult time discerning the content of these tests than humans, making the challenge useful in determining if a human or a computer is attempting access.

two-factor authentication

Authentication process that provides additional security by requiring two different authentication factors.

MFA (Multifactor Authentication)

Authentication schema requiring more than one unique authentication factor. The factors are knowledge, possession, inherence, location, and temporal. For example, a password (knowledge factor) and a fingerprint (inherence factor) is a basic form of multifactor authentication.

PKI (Public Key Infrastructure)

Authentication schema where public keys are exchanged between all parties using digital certificates, enabling secure communication over public networks.

Extensible Authentication Protocol (EAP)

Authentication wrapper that EAP-compliant applications can use to accept one of many types of authentication. While EAP is a general-purpose authentication wrapper, its only substantial use is in wireless networks.

DAC (Discretionary Access Control)

Authorization method based on the idea that there is an owner of a resource who may at his or her discretion assign access to that resource. DAC is considered much more flexible than mandatory access control (MAC).

MAC (Mandatory Access Control)

Authorization method in which the system grants access to resources based on security labels and clearance levels. Less flexible than discretionary access control (DAC), which lets the users assign access levels to resources they own. MAC may be used in organizations with very high security levels.

end process

Option in Task Manager to halt a program or background process and all of its supporting processes.

UPC (Universal Product Code)

Bar code used to track inventory

Hex (Hexadecimal)

Base-16 numbering system using ten digits (0 through 9) and six letters (A through F). In the computer world, shorthand way to write binary numbers by substituting one hex digit for a four-digit binary number (e.g., hex 9 = binary 1001).

packet

Basic component of communication over a network. Group of bits of fixed maximum size and well-defined format that is switched and transmitted as a single entity through a network. Contains source and destination address, data, and control information. Packets are included within (and are not the same thing as) a frame.

POST (power-on self test)

Basic diagnostic routine completed by a system at the beginning of the boot process to make sure a display adapter and the system's memory are installed; it then searches for an operating system. If it finds one, it hands over control of the machine to the OS.

Li-Ion (Lithium-Ion)

Battery commonly used in portable computing devices. Li-Ion batteries don't suffer from the memory effects of Nickel-Cadmium (Ni-Cd) batteries and provide much more power for a greater length of time.

Ni-MH (Nickel-Metal Hydride)

Battery used in early portable PCs. Ni-MH batteries had fewer issues with the memory effect than Ni-Cd batteries. Ni-MH batteries have been replaced by Lithium-Ion batteries. (See also Ni-Cd, Li-Ion.)

Ni-Cd (nickel-cadmium)

Battery used in the first portable PCs. Heavy and inefficient, these batteries also suffered from a memory effect that could drastically shorten the overall life of the battery. (See also Ni-MH, Li-Ion.)

pickup roller

Begins the printing process by grabbing paper to be printed and passing it over the separation pad.

measured service

Billing model cloud service providers use to charge for services in small increments based on the computing resources the customers consumes.

machine language

Binary code made up of 0s and 1s; usually this is data converted from a high-level language by a compiler. Often used as a synonym for low-level programming language understood by the CPU.

streaming media

Broadcast of data that is played on your computer and immediately discarded.

tower spoofing

Broadcasting a rogue cellular signal that imitates a legitimate cell tower in order to trick cellular devices into connecting.

malware

Broadly, software designed to use your computer or device against your wishes. Includes adware, spyware, viruses, ransomware, etc. May be part of seemingly legitimate software or installed by exploiting a vulnerability in the device.

ISO-9660

CD format to support PC file systems on CD media. Often referred to by the more generic term CD File System (CDFS).

CD-R (CD-recordable)

CD technology that accepts a single "burn" but cannot be erased after that one burn.

CD-RW (CD-rewritable)

CD technology that accepts multiple reads/writes like a hard drive.

music CD-R

CD using a special format for home recorders. Music CD-R makers pay a small royalty to avoid illegal music duplication.

clock-multiplying CPU

CPU that takes the incoming clock signal and multiples it inside the CPU to let the internal circuitry of the CPU run faster.

dual core

CPUs that have two execution units on the same physical chip but share caches and RAM.

STP (shielded twisted pair)

Cabling for networks, composed of pairs of wires twisted around each other at specific intervals. Twists serve to reduce interference (also called crosstalk)—the more twists, the less interference. Cable has metallic shielding to protect the wires from external interference.

coaxial cable

Cabling in which an internal conductor is surrounded by another, outer conductor, thus sharing the same axis.

Horizontal Cabling

Cabling that connects the equipment room to the work areas.

digital camera

Camera that records and stores digital images

sampling

Capturing sound waves in electronic format.

controller card

Card adapter that connects devices, such as a disk drive, to the main computer bus/motherboard.

Product Release Instructions (PRI)

Carrier-made updates that modify many complex settings for CDMA devices ready them for deployment on the carrier's network.

printhead

Case that holds the printwires in a dot-matrix printer.

external enclosure

Casing that encloses an external hard drive.

CAT 5

Category 5 Cable wire; an ANSI/TIA standard for UTP wiring that can operate at up to 100 Mbps.

start button

Clickable element on the Windows taskbar. Enables you to see all the programs loaded on a system and to start them.

public cloud

Cloud network built and maintained by a large company for use by any individual or company who wants to create an account and start paying for services.

Private Cloud

Cloud network built and maintained by or explicitly for a specific company or organization. Often on-site. but may be provided by a third party. While a public cloud network often requires more expertise and costs more, especially up front, it also enables greater customization and security.

community cloud

Cloud network that serves community or group with shared needs and interests, such as hospitals or defense contractors.

SaaS (Software as a Service)

Cloud-based service to store, distribute, and update programs and applications. The SaaS model provides access to necessary application wherever you have an Internet connection, often without having to carry data with your regularly update software. At the enterprise level, the subscription model of many SaaS providers makes it easier to budget and keep hundreds or thousands of computers up to date.

virtual application streaming

Cloud-based versions of local applications. Virtual application streaming enables access to programs using almost any device that can browse the Internet.

PaaS (Platform as a Service)

Cloud-based virtual server(s). These virtualized platforms give programmers tools needed to deploy, administer, and maintain a Web application.

laaS (infrastructure as a service)

Cloud-hosted provider of virtualized servers and networks.

RG-59

Coaxial cable used for cable television, cable modems, and broadcast TV; thinner than RG-6, which makes it suitable for shorter patch cables.

RG-6

Coaxial cabling used for cable television. It has a 75-ohm impedance and uses an F-type connector

signature (malware)

Code pattern of a known virus or malware that antivirus/anti-malware software uses to detect malware.

Digital Rights Management (DRM)

Code schemes for enforcing what users can and can't do with commercial software or digital media files.

product key

Code used during installation to verify legitimacy of the software.

change documentation

Collected documentation for all aspects of a change process, including plans leading up to the change as well as receipts, overtime documents, an inventory of changed systems, a list of created users, and signed end-user acceptance forms.

Plug and Play (PnP)

Combination of smart PCs, smart devices, and smart operating systems that automatically configure all necessary system resources and ports when you install a new peripheral device.

net

Command in Windows that enables users to view a network without knowing the names of the other computers on that network.

copy command

Command in the command line interface for making a copy of a file and pasting it in another location.

xcopy

Command in the command-line interface used to copy multiple directories at once, which the copy command could not do.

md (mkdir)

Command in the command-line interface used to create directories.

del (erase)

Command in the command-line interface used to delete/erase files.

format

Command in the command-line interface used to format a storage device.

move

Command in the command-line interface used to move a file from one location to another.

rd (rmdir)

Command in the command-line interface used to remove directories.

pipe

Command-line operator that uses the | symbol to "pipe" output from one command to another, instead of printing it to the screen.

nslookup

Command-line program in Windows used to determine exactly what information the DNS server is providing about a specific host name.

reg

Command-line tool for editing the Registry.

netstat

Command-line tool in Windows and Linux to identify inbound and outbound TCP/IP connections with the host.

Windows PowerShell

Command-line tool included with Windows. Offers a number of powerful scripting tools for automating changes both on local machines and over networks.

dir

Command-line tool used to display the entire contents of the current working directory.

sfc (System File Checker)

Command-prompt program (sfc.exe) that scans, detects, and restores Windows system files, folders, and paths.

F-type connector

Common coax connector secured with a screw connector.

serial port

Common connector on older PC. Connects input devices (such as a mouse) or communications devices (such as a modem). Also referred to as a COM port.

Wi-Fi

Common name for the IEEE 802.11 wireless Ethernet standard.

TCP/IP (Transmission Control Protocol/Internet Protocol)

Communication protocols developed by the U.S. Department of Defense to enable dissimilar computers to share information over a network. TCP/IP is the primary protocol of most modern networks, including the Internet.

eliciting answers

Communication strategy designed to help techs understand a user's problems better. Works by listening to a user's description of a problem and then asking cogent questions.

thick client

CompTIA's name for a standard desktop computer. Runs desktop applications and meets recommended requirements for selected OS. It does not need a network connection to run.

Pearson VUE

Company that administers the CompTIA A+ exams.

ISO file

Complete copy (or image) of a storage media device, typically used for optical discs. ISO image files typically have a file extension of .iso.

Zigbee

Completely open wireless networking protocol designed to address home automation challenges.

Registry

Complex binary file used to store configuration data about a particular Windows system. To edit the Registry, users can use the applets found in the Control Panel or regedit.exe or regedt32.exe.

RIP (Raster Image Processor)

Component in a printer that translates the raster image into commands for the printer.

erase lamp

Component inside laser printers that uses light to make the coating of the photosensitive drum conductive.

GDI (graphical device interface)

Component of Windows that utilizes the CPU rather than the printer to process a print job as a bitmapped image of each page.

rainbow table

Compressed file that contains a mapping of hashed passwords (or other account information) to the corresponding unhashed, plaintext password. Rainbow tables are useful for reversing unsalted hashes in older/legacy authentication systems, but are useless for reversing properly salted hashes used by well-designed, modern authentication systems.

file server

Computer designated to store software, courseware, administrative tools, and other data on a LAN or WAN. It "serves" this information to other computers via the network when users enter their personal access codes.

VR (Virtual Reality)

Computer generated 3-D video and audio paired with special hardware (usually including a VR headset and sensors to detect movement) to create an immersive simulation a user navigates by moving around in physical space.

zombie

Computer infected with malware that has turned it into a botnet member.

video capture

Computer jargon for the recording of video information, such as TV shows or movies.

Molex connector

Computer power connector used by optical drives, hard drives, and case fans. Keyed to prevent it from being inserted into a power port improperly.

client

Computer program that uses the services of another computer program. Also, software that extracts information from a server; your auto-dial phone is a client, and the phone company is its server. Also, a machine that accesses shared resources on a server.

server

Computer that shares its resources, such as printers and files, with other computers on a network. Example: network file system server that shares its disk space with a workstation that does not have a hard disk drive of its own.

compliance

Concept that members of an organization must abide by the rules created by and applying to that organization (including government regulations). For a technician, this often defines what software can or cannot be installed on an organization's computers.

parallel port

Connection for the synchronous, high-speed flow of data along parallel lines to a device, usually a printer.

Transmission Control Protocol (TCP)

Connection-oriented protocol used with TCP/IP.

User Datagram Protocol (UDP)

Connectionless protocol used with TCP/IP.

expansion slots

Connectors on a motherboard that enable users to add optional components to a system. (See also AGP, PCI, and PCIe.)

HBA (host bus adapter)

Connects SATA devices to the expansion bus. Also known as the SATA controller.

IEC-320

Connects the cable supplying AC power from a wall outlet into the power supply.

resource pooling

Consolidating resources from many systems into a smaller number of more powerful systems, reducing power, maintenance, and hardware costs.

PCMCIA (Personal Computer Memory Card International Association)

Consortium of computer manufacturers who devised the PC Card standard for credit card-sized adapter cards that add functionality in older notebook computers and other computer devices. PCMCIA shut down in 2009.

user account

Container that identifies a user to an application, operating system, or network, including name, password, user name, groups to which the user belongs, and other information based on the user and the OS being used. Usually defines the rights and roles a user plays on a system.

system tray

Contains icons representing background processes and the system clock. Located by default at the right edge of the Windows taskbar. Accurately called the notification area.

notification area

Contains the Show hidden icons button, one notification icon, and the current time

File History

Control Panel applet introduced in Windows 8 for backing up personal files and folders.

loop

Control construct used in a script or program to repeat a sequence of instructions when certain conditions are met. For example, a script could use a loop to a set of instructions for resizing an image once for every image file in a directory.

policies

Control permission to perform a given action, such as accessing a command prompt, installing software, or logging on at a certain time of day. Contrast with true permissions, which control access to specific resources.

expansion bus crystal

Controls the speed of the expansion bus.

power management

Cooperation between hardware, BIOS, and OS to reduce power consumption.

printed circuit board (PCB)

Copper etched onto a nonconductive material and then coated with some sort of epoxy for strength.

cp

Copy command in Linux

kernel

Core portion of program that resides in memory and performs the most essential operating system tasks.

thin provisioning

Creating a Storage Space that reports a size greater than the actual capacity installed in the computer, with the ability to later add more physical capacity up to the reported size

tunneling

Creating an encrypted link between two programs on two separate computers.

User Password

Credentials assigned to a login account that does not have administrative capabilities.

burn-in failure

Critical failure usually associated with manufacturing defects.

System Crystal

Crystal that provides the speed signals for the CPU and the rest of the system.

DB connectors

D-shaped connectors used for a variety of connections in the PC and networking world. Can be male (with prongs) or female (with holes) and have a varying number of pins or sockets. Also called D-sub, D-subminiature, or D-shell connectors.

catastrophic failure

Describes a failure in which a component or whole system will not boot; usually related to a manufacturing defect of a component. Could also be caused by overheating and physical damage to computer components.

Open Source

Describes a product for which the plans, schematics, recipes, or other information used to create it are released by its creator or distributor. Most commonly applied to software.

UNC (Universal Naming Convention)

Describes any shared resource in a network using the convention \\<server name>\<name of shared resource>.

registration (printing)

Describes how accurately the printer lays down each color layer that makes up a page or image. Poor registration can result in muddled colors or a fringe of pure color around a shape or image. Printers usually have a routine (which may mention calibration, alignment, or registration) for detecting and fixing alignment issues.

monoaural

Describes recording tracks from one source (microphone) as opposed to stereo, which uses two sources.

stereo

Describes recording tracks from two sources (microphones) as opposed to monaural, which uses one source.

nonvolatile

Describes storage that retains data even if power is removed; typically refers to a ROM or flash ROM chip, but also could be applied to hard drives, optical media, and other storage devices.

polarization

Describes the alignment (such as vertical or horizontal) of antennas and the signals they transmit. Because of polarization, a Wi-Fi client and WAP will have the best connection when their antennas are oriented.

permission propagation

Describes what happens to permissions on any object, such as a file or folder, when you move or copy it.

screen orientation

Describes whether a mobile device screen is in portrait or landscape mode, and the device settings that govern when the orientation may change. When the screen orientation setting is in automatic mode, the user interface will switch between portrait and landscape modes based on the devices orientation in physical space.

PCI (Peripheral Component Interconnect)

Design architecture for the expansion bus on the computer motherboard that enables system components to be added to the computer. Local bus standard, meaning that devices added to a computer through this port will use the processor at the motherboard's full speed (up to 33 MHz) rather than at the slower 8-MHz speed of the regular bus. Moves data 32 or 64 bits at a time rather than the 8 or 16 bits the older ISA buses supported.

ISA (Industry Standard Architecture)

Design found in the original IBM PC for the slots that allowed additional hardware to be connected to the computer's motherboard. An 8-bit, 8.33-MHz expansion bus was designed by IBM for its AT computer and released to the public domain. An improved 16-bit bus was also released to the public domain. Replaced by PCI in the mid-1990s.

NLQ (near-letter quality)

Designation for dot-matrix printers that use 24-pin printheads.

modem (modular/demodulator)

Device that converts a digital bit stream into an analog signal (modulation) and converts incoming analog signals back into digital signals (demodulation). An analog communications channel is typically a telephone line, and analog signals are typically sounds.

USB hub

Device that extends a single USB connection to two or more USB ports, almost always directly from one of the USB ports connected to the root hub.

VoIP phone

Device that looks like a regular landline phone but uses VoIP to communicate over a computer network.

speaker

Device that outputs sound by using magnetically driven diaphragm.

port replicator

Device that plugs into a USB port or other specialized port and offers common PC ports, such as serial, parallel, USB, network, and PS/2. By plugging your note- book computer into the port replicator, you can instantly connect the computer to non-portable components such as a printer, scanner, monitor, or full-sized keyboard. Port replica- tors are typically used at home or in the office with the non- portable equipment already connected.

docking station

Device that provides a portable computer extra features such as a DVD drive or PC Card, in addition to legacy and modern ports. Similar to a port replicator. Also, a charging station for mobile devices

Firewall

Device that restricts traffic between a local network and the Internet.

smart card reader

Device that scans the smart card chip, such as those in ID badges. Common applications include enhancing the security of doors or laptops.

UPS (uninterruptible power supply)

Device that supplies continuous clean power to a computer system the whole time the computer is on. Protects against power outages and sags.

loopback plug

Device used during loopback tests to check the female connector on a NIC.

multimeter

Device used to measure voltage, amperage, and resistance.

card reader

Device with which you can read data from one of several types of flash memory.

real-time clock (RTC)

Device within the CMOS memory chip that provides date and time information to the computer and operating system.

fitness monitor

Devices that encourage physical fitness by counting steps using accelerometers, registering heart rate through sensors, using GPS to track exercise, and offering vibration tools to remind the user to get moving. Fitness trackers fit into one of two type: fobs that clip to the body and more sophisticated fitness bands or watches.

driver signing

Digital signature for drivers used by Windows to protect against potentially bad drivers.

DisplayPort

Digital video connector used by Apple Mac desktop models and some PCs, notably from Dell. Designed by VESA as a royalty-free connector to replace VGA and DVI.

root directory

Directory that contains all other directories.

RAID 6

Disk striping with extra parity. Like RAID 5, but with more parity data. Requires five or more drives, but you can lose up to two drives at once and your data is still protected.

Native Command Queuing (NCQ)

Disk-optimization feature for SATA drives enabling faster read and write speeds

fdisk

Disk-partitioning utility used in DOS and Windows 9x systems.

DLP (digital light processing)

Display technology that reflects and directs light onto a display surface using micromechanically operated mirrors.

IPS (In Plane Switching)

Display technology that replaces the older twisted nematic (TN) panels for more accurate colors and a wider viewing angle.

Vertical Alignment (VA)

Display technology used in mid-range LCD panels. VA refers to how the liquid crystal matrix is arranged within the panel.

OLED (organic light-emitting diode)

Display technology where an organic compound provides the light for the screen, thus eliminating the need for a backlight or inverter. Used in high end TVs and small devices such as smart watches, smartphones, and VR headsets.

rearview projector

Display using a projector that illuminates a semi-transparent screen from the back. Once popular for televisions, but virtually unheard of for PCs.

entry control roster

Document for recording who enters and leaves a building

BitLocker Drive Encryption

Drive encryption software offered in high-end versions of Windows. BitLocker requires a special chip to validate hardware status and to ensure that the computer hasn't been hacked.

mount point

Drive that functions like a folder mounted into another drive.

optical drive

Drive used to read/write to optical discs, such as CDs or DVDs.

unsigned driver

Driver that has not gone through the Windows Certification Program to ensure compatibility. The Windows Certification Program was formerly known as the Windows Hardware Quality Labs and the Microsoft Windows Logo Program.

terminal

Dumb device connected to a mainframe or computer network that acts as a point for entry or retrieval of information.

parity RAM

Earliest form of error-detecting RAM; stored an extra bit (called the parity bit) to verify the data.

parity

Early method of error detection where a small group of bits being transferred is compared to a single parity bit set to make the total bits odd or even. The receiving device reads the parity bit and determines if the data is valid, based on the oddness or evenness of the parity bit.

electromagnetic interference (EMI)

Electrical interference from one device to another, resulting in poor performance of the device being interfered with. Examples: Static on your TV while running a blow dryer, or placing two monitors too close together and getting a "shaky" screen.

chipset

Electronic chips, specially designed to work together, that handle all of the low-level functions of a PC. In the original PC, the chipset consisted of close to 30 different chips; today, chipsets usually consist of one, two, or three separate chips embedded into a motherboard.

hub

Electronic device that sits at the center of a star topology network, providing a common point for the connection of network devices. Hubs repeat all information out to all ports and have been replaced by switches, although the term "hub" is still commonly used.

ohm(s)

Electronic measurement of a cable's impedance.

partitioning

Electronically subdividing a physical hard drive into groups called partitions (or volumes).

Firmware

Embedded programs or code stored on a ROM chip. Generally OS-independent, thus allowing devices to operate in a wide variety of circumstances without direct OS support. The system BIOS is firmware.

PPP (Point-to-Point Protocol)

Enables a computer to connect to the Internet through a dial-in connection and enjoy most of the benefits of a direct connection.

VPN (Virtual Private Network)

Encrypted connection over the Internet between a computer or remote network and a private network.

Transport Layer Security (TLS)

Encryption protocol used to securely connect between servers and clients, such as when your Web browser securely connects to Amazon's servers to make a purchase. Replaces SSL.

MFT (master file table)

Enhanced file allocation table used by NTFS. (See also FAT.)

system/application log errors

Errors and warnings in the system/application logs may indicate the presence of a malware infestation and the scope of its effects.

General Data Protection Regulation (GDPR)

European Union law that defines a broad set of rights and protections of personal information for citizens of the EU.

msconfig (System Configuration utility)

Executable file that runs the Windows System Configuration utility, which enables users to configure a system's boot files and critical system files. Often used for the name of the utility, as in "just run msconfig."

NIC (network interface card or controller)

Expansion card or motherboard interface that enables a PC to connect to a network via a network cable. A wireless NIC enables connection via radio waves rather than a physical cable.

sound card

Expansion card that can produce audible tones when connected to a set of speakers.

MIDI-enabled device

External device that enables you to input digital sound information in the MIDI format; for example, a MIDI keyboard (the piano kind).

password reset disc

External storage media such as an optical disc or USB flash drive with which users can recover a lost password without losing access to any encrypted; if a user loses a password and did not already make a reset disc, it will be of no help to create one after the loss.

HTTP (Hypertext Transfer Protocol)

Extremely fast protocol used for network file transfers on the World Wide Web. Uses port 80

distended capacitors

Failed capacitors on a motherboard, which tend to bulge out at the top. This was especially a problem during the mid-2000s, when capacitor manufacturers released huge batches of bad capacitors

Library

Feature in Windows 7 and later that aggregates folders from multiple locations and places them in a single, easy-to-find spot in Windows Explorer or File Explorer. Default libraries in Windows include Documents, Music, Pictures, and Videos.

Geotracking

Feature in cellular phones that enables the cell phone companies and government agencies to use the ID or MAC address to pinpoint where your phone is at any given time.

side-by-side apps

Feature introduced in Windows 8 for quickly pinning an app to the left or right half of a screen

MIMO (multiple input-multiple output)

Feature of 802.11n devices that enables the simultaneous connection of up to four antennas, greatly increasing throughput. 802.11ac also uses MU-MIMO, which gives a WAP the capability to broadcast to multiple users simultaneously.

object access auditing

Feature of Event Viewer's Security section that creates an entry in the Security Log when certain objects are accessed, such as a file or folder.

event auditing

Feature of Event Viewer's Security section that creates an entry in the Security Log when certain events happen, such as a user logging on.

Remote Assistance

Feature of Windows that enables users to give anyone control of his or her desktop over the Internet.

compatibility modes

Feature of Windows to enable software written for previous versions of Windows to operate in newer operating systems

chassis intrusion detection

Feature offered in some chassis that trips a switch when the chassis is opened.

auto-brightness

Feature on modern mobile devices that attempts to use a camera or other light sensor to adjust screen brightness based on how light or dark it is.

quad-channel architecture

Feature similar to dual-channel RAM, but requiring four sticks instead of two.

metered service

Fee charged by cloud providers on the basis of how much of a resource was used. Fees may be based on things like access time, bandwidth used, bytes uploaded or downloaded, CPU usage, and other resource usage metrics.

Information Technology (IT)

Field of computers, their operation, and their maintenance.

GDDR5

Fifth generation of graphical DDR RAM found on high-performance video cards.

security tab

File/folder administrative preferences found in the Properties dialog in both File Explorer and Windows Explorer. These preferences govern user and group access to a particular file or folder.

log files

Files created in Windows to track the progress of certain processes.

definition file

Files that enable anti-malware programs to identify viruses on your system and clean them. These files should be updated often. Also called signature files.

IEEE 1394a

FireWire standard that runs at 400 Mbps.

IEEE 1394b

FireWire standard that runs at 800 Mbps.

software firewall

Firewall implemented in software running on servers or workstations.

hardware firewall

Firewall implemented within networking hardware such as a router.

Level 1 (L1) cache

First RAM cache accessed by the CPU, which stores only the absolute most-accessed programming and data used by currently running threads. Always the smallest and fastest cache on the CPU.

DOS (Disk Operating System)

First popular operating system available for PCs. A text-based, single-tasking operating system that was not completely replaced until the introduction of Windows 95.

logon screen

First screen of the Windows interface, used to log on to the computer system.

boot sector

First sector on a PC hard drive or floppy disk, track 0. The boot-up software in ROM tells the computer to load whatever program is found there. If a system disk is read, the program in the boot record directs the computer to the root directory to load the operating system

root keys

Five main categories in the Windows Registry: HKEY_CLASSES_ROOT HKEY_CURRENT_USER HKEY_USERS HKEY_LOCAL_MACHINE HKEY_CURRENT_CONFIG

Boot Sequence

List containing information telling the bootstrap loader in which order to check the available storage devices for an OS. Configurable in CMOS setup.

spindle speed

Fixed speed in revolutions per minute (RPM) at which a given HDD's platters spin. The two most common speeds are 5400 and 7200 RPM; higher performance drives (far less common) run at 10,000 and 15,000 RPM. Also called rotational speed.

system ROM

Flash ROM chip that stores the system BIOS.

USB thumb drive

Flash memory device that uses the standard USB connection.

motherboard

Flat piece of circuit board that resides inside your computer case and has a number of connectors on it. Every device in a PC connects directly or indirectly to the motherboard, including CPU, RAM, hard drives, optical drives, keyboard, mouse, and video cards.

Public folder

Folder that all users can access and share with all other users on the system or network.

extra battery pack

For devices with removable batteries, an extra battery that can be swapped in as needed.

hard reset

For mobile devices, another term for a factory reset. Don't confuse this with a hard reboot.

digital certificate

Form in which a public key is sent from a Web server to a Web browser so that the browser can decrypt the data sent by the server.

dual-channel memory

Form of DDR, DDR2, and DDR3 memory access used by many motherboards that requires two identical sticks of DDR, DDR2, or DDR3 RAM.

tailgating

Form of infiltration and social engineering that involves following someone else through a door as if you belong in the building.

FPU (floating point unit)

Formal term for math coprocessor (also called a numeric processor) circuitry inside a CPU. A math coprocessor calculates by using a floating point numerical system (which allows for decimals). Before the Intel 80486, FPUs were separate chips from the CPU.

Full Format

Format process that tests every sector to mark out the unusable ones in the file association table (FAT).

high-level formatting

Format that sets up a file system on a drive.

computing process

Four parts of a computer's operation: input, processing, output, and storage.

Long Term Evolution (LTE)

Fourth-generation cellular network technology supporting theoretical download speeds up to 1 Gbps and upload speeds up to 100 Mbps. Marketed as and now generally accepted as a true 4G technology.

Protected Health Information (PHI)

Personally identifiable information that includes an individual's medical and health history.

rogue anti-malware

Free applications that claim to be anti-malware, but which are are actually

conditionals

Functions that enable a script or program to perform different actions under different conditions. For example, a backup script might "run" every hour, but only create a new backup if the system is idle and if it has been at least a day since the last backup was created.

System Monitor

GNOME 3 utility that can evaluate and monitor system resources, such as CPU usage and memory usage.

integrated GPU

GPU integrated with the motherboard or processor, in contrast to GPUs on separate graphics cards. This typically lowers power consumption, saves space, reduces heat, and may speed up communication with the GPU.

content filtering

Gaining access to insecure or objectionable sites using certificates or parental control tools.

dynamic range

Gamut of color or intensity of light that can be displayed or detected by a device.

I/O (input/output)

General term for reading and writing data to a computer. "Input" includes data entered from a keyboard, identified by a pointing device (such as a mouse), or loaded from a disk. "Output" includes writing information to a disk, viewing it on a monitor, or printing it to a printer.

USB (Universal Serial Bus)

General-purpose serial interconnect for keyboards, printers, joysticks, and many other devices. Enables hot-swapping of devices.

CDFS (Compact Disc File System)

Generic name for ISO-9660. File structure, rules, and conventions used when organizing and storing files and data on a CD.

stick

Generic name for a single physical SIMM, RIMM, or DIMM.

ROM (Read Only Memory)

Generic term for nonvolatile memory that can be read from but not written to. This means that code and data stored in ROM cannot be corrupted by accidental erasure. Additionally, ROM retains its data when power is removed, which makes it the perfect medium for storing BIOS data or information such as scientific constants.

toner (networking)

Generic term for two devices used together - a tone generator and a tone probe (locator) - to trace cables by sending an electrical signal along a wire at a particular frequency. The tone probe then emits a sound when it distinguishes that frequency.

vendor specific

Generically, a proprietary product or technology that doesn't use common, open standards. Vendor-specific products or features may not be completely or even partially compatible with products from other vendors. Also applies to stores that only sell products from one manufacturer, like the Apple store.

key fob

Generically, just about anything attached to a key ring that isn't a key. Some security tools, such as hardware security tokens and RFID authentication devices, are commonly designed as key fobs.

remote desktop

Generically, the process of using one system to access the desktop or graphical user interface of a remote system.

swipe

Gesture for mobile devices where you hold your finger on the screen and slide it across the screen, either right to left or top to bottom, depending on the type of application.

Ethic of Reciprocity

Golden Rule: Do unto others as you would have them do unto you.

Chrome OS

Google's Linux-based operating system designed to work primarily with web apps.

GooglePlay

Google's app and media store for Android devices.

printwires

Grid of tiny pins in a dot-matrix printer that strike an inked printer ribbon to produce images on paper.

ESD strap

Ground bracelet. A strap you wear around your wrist that is attached to the computer case, ground mat, or another ground so that ESD is discharged from your body before you touch sensitive components inside a computer.

LAN (Local Area Network)

Group of computers connected via cabling, radio, or infrared that use this connectivity to share resources such as printers and mass storage.

Domain

Groupings of users, computers, or networks. In Microsoft networking, a domain is a group of computers and users that share a common account database and a common security policy. On the internet, a domain is a group of computers that share a common element in their hierarchical name. Other types of domains exist - e.g., broadcast domain, etc.

display adapter

Handles all the communication between the CPU and the monitor. Also known as a video card.

Personalization Settings

Handles user preferences such as the background picture for both the desktop and lock screen, colors of interface elements, themes, which elements show on the Start screen, and so on. Replaced the Personalization applet in Windows 10.

chkdsk (CheckDisk)

Hard drive error detection and, to a certain extent, correction utility in Windows, launched from the command-line interface. Originally a DOS command (chkdsk.exe); also the executable for the graphical Error-checking tool.

basic disk

Hard drive partitioned in the "classic" way with a master boot record (MBR) and partition table. (See also dynamic disks.)

Disk Thrashing

Hard drive that is constantly being accessed due to lack of available system memory. When system memory runs low, a Windows system will utilize hard disk space as "virtual" memory, thus causing an unusual amount of hard drive access.

mass storage

Hard drives, optical discs, removable media drives, etc.

smart card

Hardware authentication involving a credit card-sized card with circuitry that can be used to identify the bearer of that card.

plug

Hardware connection with some sort of projection that connects to a port.

KVM (Keyboard, Video, and Mouse) switch

Hardware device that enables multiple computers to be viewed and controlled by a single mouse, keyboard, and screen.

service menu

Hidden device menu containing tools for technicians servicing the device. May contain diagnostics, reports, or interfaces for changing otherwise inaccessible settings.

diagnostics menu

Hidden mobile device menu that contains tests and diagnostics for verifying the functionality of various device hardware.

FAT (File Allocation Table)

Hidden table that records how files on a hard disk are stored in distinct clusters; the only way DOS knows where to access files. Address of first cluster of a file is stored in the directory file. FAT entry for the first cluster is the address of the second cluster used to store that file. In the entry for the second cluster for that file is the address for the third cluster, and so on until the final cluster, which gets a special end-of-file code. There are two FATs, mirror images of each other, in case one is destroyed or damaged. Also refers to the 16-bit file allocation table when used by Windows 2000 and later NT-based operating systems.

Audio Interface

High-end external sound device used by Audio engineers and recording artists.

quick format

High-level formatting that creates just the file allocation table and a blank root directory

S/PDIF (Sony/Philips Digital Interface Format)

High-quality digital audio connector. Users can connect their computers directly to a 5.1 speaker system or receiver with a single cable. S/PDIF comes in both a coaxial version and an optical version.

DSL (digital subscriber line)

High-speed Internet connection technology that uses a regular telephone line for connectivity. DSL comes in several varieties, including asynchronous (ADSL) and synchronous (SDSL), and many speeds. Typical home-user DSL connections are ADSL with faster download speeds than upload speeds.

fiber-optic cable

High-speed cable for transmitting data, made of high-purity glass sealed within an opaque tube. Much faster than conventional copper wire such as coaxial cable. Most common connectors include ST, SC, and LC.

DLT (digital linear tape)

High-speed, magnetic tape storage technology used to archive and retrieve data from faster, online media such as hard disks.

print resolution

How densely a printer lays down ink on the page - more dense means higher quality picture. Measured in "dots per inch" (dpi)

file format

How information is encoded in a file. Two primary types are binary (pictures) and ASCII (text), but within those are many formats, such as BMP and GIF for pictures. Commonly represented by a suffix at the end of the filename; for example, .txt for a text file or .exe for an executable.

TrackPoint

IBM's pencil eraser-sized joystick used in place of a mouse on laptops.

IEEE 1394

IEEE standard governing for FireWire communication.

link-local address

IPv6 address a computer gives itself when it first boots. IPv6's equivalent to IPv4's APIPA address.

PATA (Parallel ATA)

Implementation that integrates the controller on the disk drive itself. (See also ATA, IDE, SATA.)

Safe Mode

Important diagnostic boot mode for Windows that runs only very basic drivers and turns off virtual memory.

Enhanced 911 (E-911)

Improves 911 service for cellular phones by using GPS and cellular network triangulation to locate the device and dispatch emergency responders.

port (networking)

In networking, the number used to identify the requested service (such as SMTP or FTP) when connecting to a TCP/IP host. Examples: 80 (http), 443 (HTTPS), 21 (FTP), 23 (Telnet), 25 (SMTP), 110 (POP3), 143 (IMAP), and 3389 (RDP).

DPI (dots per inch)

Measure of printer resolution that counts the dots the device can produce per linear (horizontal) inch.

charms

In Windows 8 and 8.1, tools located in the hidden Charms bar, such as a search function, a sharing tool, a settings tool, and more.

Storage spaces

In Windows 8 and later, a software RAID solution that enables users to group multiple drives into a single storage pool

Personalization applet

In Windows 8.1 and earlier, this Control Panel applet handles user preferences such as the background picture, colors of various interface elements, and so on.

default gateway

In a TCP/IP network, the nearest router to a particular host. This router's IP address is part of the necessary TCP/IP configuration for communicating with multiple networks using IP.

work area

In a basic structured cabling network, often simply an office or cubicle that potentially contains a PC attached to the network

owner

In both NTFS and UNIX permissions, the owner is usually the user that created a given file or folder, although both systems support changing ownership to another user.

backout plan

In case a change doesn't go as planned, a set of steps necessary to undo the change and restore the infrastructure to its previous state.

system resources

In classic terms, the I/O addresses, IRQs, DMA channels, and memory addresses. Also refers to other computer essentials such as hard drive space, system RAM, and processor speed.

pixel (picture element)

In computer graphics, smallest element of a display space that can be independently assigned color or intensity.

transfer roller

In more recent laser printers, replaces the transfer corona, but performs the same task: applying a positive charge to the paper to draw toner from the imaging drum to the paper.

northbridge

In older chipsets, a chip that connects a CPU to memory, the PCI bus, Level 2 cache, and high-speed graphics. Communicates with the CPU though the frontside bus. Newer CPUs feature an integrated northbridge.

southbridge

In older chipsets, a chip that handled all the inputs and outputs to the many devices in the PC.

trigger port

In port triggering, outbound traffic on this port will cause the router to open the destination port and wait for a response.

destination port

In port triggering, the port that the router opens to receive a response after the router sends outbound traffic on the trigger port.

string

In programming and scripting, a non-numeric sequence of alphanumeric data.

variables

In scripting and programming, named labels for some portion of in-memory data. The actions taken by the script or program may change or replace the data in the variable.

incident response leader

In some organizations, a person other than a supervisor responsible for receiving and responding to all incident reports.

DVD-RW/DVD+RW

Incompatible rewritable DVD media formats.

bit depth

Indicates the number of signal characteristics a device can capture or produce, or the number recorded in a file. Greater bit depths mean more characteristics can be captured, stored, and reproduced. Often used to describe the quality of audio or video signals.

surge suppressor

Inexpensive device that protects your computer from voltage spikes.

BSoD (Blue Screen of Death)

Infamous error screen that appears when Windows encounters an unrecoverable error.

location data

Information provided by a mobile device's GPS; used for mapping functions as well as for location-aware services, such as finding nearby restaurants or receiving coupons for nearby shops.

SPD (serial presence detect)

Information stored on a RAM chip that describes the speed, capacity, and other aspects of the RAM chip.

high gloss

Laptop screen finish that offers sharper contrast, richer colors, and wider viewing angles than a matte finish, but is also much more reflective.

mouse

Input device used to control a cursor or pointer.

keyboard

Input device. Three common types of keyboards exist: those that use a mini-DIN (PS/2) connection, those that use a USB connection, and those that use wireless technology.

multitouch

Input method on many smartphones and tablets that enables you to use multiple fingers to do all sorts of fun things, such as using two fingers to scroll or swipe to another screen or desktop.

upgrade installation

Installation of Windows on top of an earlier installed version, thus inheriting all previous hardware and software settings.

clean installation

Installing an operating system on a fresh drive, following a reformat of that drive. often it's the only way to correct a problem with a system when many of the crucial operating system files have become corrupted.

USB host controller

Integrated circuit that is usually built into the chipset and controls every USB device that connects to it.

Hyper-Threading

Intel CPU technology that enables a single processor core to work with two execution threads at the same time.

Platform Controller Hub (PCH)

Intel's name for the chip that collects functions once performed by multiple chips known as the chipset.

session hijacking

Intercepting a valid computer session to get authentication information from it, enabling the attacker to use whatever resources the authentication grants access for as long as the authentication information or session is valid.

FireWire (IEEE 1394)

Interconnection standard to send wide-band signals over a serialized, physically thin connector system. Serial bus developed by Apple and Texas Instruments; enables connection of 63 devices at speeds up to 800 Mbps.

MIDI (Musical Instrument Digital Interface)

Interface between a computer and a device for simulating musical instruments. Rather than sending large sound samples, a computer can simply send "instructions" to the instrument describing pitch, tone, and duration of a sound. MIDI files are therefore very efficient. Because a MIDI file is made up of a set of instructions rather than a copy of the sound, modifying each component of the file is easy. Additionally, it is possible to program many channels, or "voices," of music to be played simultaneously, creating symphonic sound.

Network

Interface in File Explorer or Windows Explorer; displays networked computers and other devices, such as network printers.

IPv4 (Internet Protocol version 4)

Internet standard protocol that provides a common layer over dissimilar networks; used to move packets among host computers and through gateways if necessary. Part of the TCP/IP protocol suite. Uses the dotted-decimal format—xxx.xxx.xxx.xxx. Each x represents an 8-bit binary number, or 0-255. Here's an example 192.168.4.1

cloud file storage services

Internet-based shared file storage spaces that enable users to save, edit, share, and collaborate on stored files, as well as synchronize files among multiple devices and users.

NMI (non-maskable interrupt)

Interrupt code sent to the processor that cannot be ignored. Typically manifested as a BSoD.

pop-up

Irritating browser window that appears automatically when you visit a Web site.

CFS (Command File System)

Just know this stands for Command File System or Common File System.

Windows logo key

Key on a keyboard bearing the Windows logo that traditionally brings up the Start menu, but is also used in some keyboard shortcuts.

password

Key used to verify a user's identity on a secure computer or network.

PostScript

Language defined by Adobe Systems, Inc., for describing how to create an image on a page. The description is independent of the resolution of the device that will actually create the image. It includes a technology for defining the shape of a font and creating a raster image at many different resolutions and sizes.

matte

Laptop screen finish that offers a good balance between richness of colors and reflections, but washes out in bright light.

knowledge base

Large collection of documents and FAQs that is maintained by Microsoft. Found on Microsoft's Web site, the Knowledge Base is an excellent place to search for assistance on most operating system problems.

static charge eliminator

Laser printer component that removes the static charge from paper to prevent the paper from wrapping around the imaging drum.

IEEE (Institute of Electronic and Electrical Engineers)

Leading standards-setting group in the United States.

trusted source

Legitimate app stores run by the major OS vendors such as Apple, Google, Microsoft, and Amazon.

tiers

Levels of Internet providers, ranging from the Tier 1 backbones to Tier 3 regional networks.

lamp

Light source in a projector.

CCFL (cold cathode fluorescent lamp)

Light technology used in LCDs and flatbed scanners. CCFLs use relatively little power for the amount of light they provide.

Xeon

Line of Intel CPUs designed for servers

vi

Linux and macOS command-line tool for editing text files.

passwd

Linux command for changing a user's password

dd

Linux command for copying entire block volumes.

rm

Linux command for deleting files

ifconfig

Linux command for finding out a computer's IP address information

sudo

Linux command for gaining root access

ps

Linux command for listing all processes running on the computer.

Users group

List of local users not allowed, among other things, to edit the Registry or access critical system files. They can create groups, but can only manage the groups they create.

local user account

List of user names and their associated passwords with access to a system, contained in an encrypted database.

Network ID

Logical number that identifies the network on which a device or machine exists. This number exists in TCP/IP and other network protocol suites

global user account

Login information and associated settings maintained at a location accessible by any computer, irrespective of location or local account configuration.

SCSI (Small Computer System Interface)

Long-lived storage drive technology once common in the server market. Has been through many iterations. Today, the SCSI command set lives on in Serial Attached SCSI (SAS) hard drives.

shoulder surfing

Looking for credentials or other sensitive information by watching someone use a computer or device, often over their shoulder.

DDR3L

Low voltage version of DDR3. Provides cost savings in large deployments, such as data center.

Celeron

Lower-cost brand of Intel CPUs.

Disk Utility

Mac OS X tool that checks for hard drive errors

Finder

Mac OS X's file and folder browser.

dedicated server

Machine that is not used for any client functions, only server functions.

sector

Magnetically preset storage areas on traditional magnetic hard drives. On older hard drives, a sector held 512 bytes of data; modern drives use 4096 byte advanced format sectors.

system unit

Main component of the PC, in which the CPU, RAM, CD-ROM, and hard drive reside. All other devices—the keyboard, mouse, and monitor—connect to the system unit.

Encryption

Making data unreadable by those who do not possess a key or password.

Verify full system functionality and, if applicable, implement preventive measures.

Making sure that a problem has been resolved and will not return. (Step 5 of 6 in the CompTIA troubleshooting methodology)

file-level backup

Manually or automatically copying individual files or folders to one or more backup locations.

static IP address

Manually set IP address that will not change

EIDE (Enhanced IDE)

Marketing concept of hard drive-maker Western Digital, encompassing four improvements for IDE drives, including drives larger than 528 MB, four devices, increase in drive throughput, and non-hard drive devices.

PVC (polyvinyl chloride)

Material used to make the plastic protective sheathing around many basic network cables. Produces noxious fumes when burned.

consumables

Materials used up by printers, including paper, ink, ribbons, and toner cartridges.

direct LED backlighting

Matrix of LEDs that illuminates a display from directly behind the display panel.

interface

Means by which a user interacts with a piece of software.

group policy

Means of easily controlling the settings of multiple network clients with policies such as setting minimum password length or preventing Registry edits.

shared memory

Means of reducing the amount of memory needed on a video card by borrowing from the regular system RAM, which reduces costs but also decreases performance.

frequency

Measure of a sounds' tone, either high or low.

resolution

Measurement for monitors and printers expressed in horizontal and vertical dots of pixels. Higher resolutions provide sharper details and thus display better-looking images.

wattage (watts or W)

Measurement of the amps and volts needed for a particular device to function.

volts (V)

Measurement of the pressure of the electrons passing through a wire, or voltage

duplexing assembly

Mechanical feature of some printers that can automatically flip the paper to print on both sides.

fuser assembly

Mechanism in laser printers that uses two rollers to fuse toner to paper during the print process.

boot method

Media a computer uses to initiate the booting process. Includes optical media, removable drives, or a networked location.

IMC (integrated memory controller)

Memory controller circuitry built into the CPU that enables faster control over things like the large L3 cache shared among multiple cores.

RAM (Random Access Memory)

Memory that can be accessed at random—that is, memory which you can write to or read from without touching the preceding address. This term is often used to mean a computer's main memory.

volatile

Memory that must have constant electricity to retain data. Alternatively, any programmer six hours before deadline after a non-stop, 48hour coding session, running on nothing but caffeine and sugar.

SO-DIMM (small outline DIMM)

Memory used in portable PCs because of its small size

DRAM (dynamic random access memory or dynamic RAM)

Memory used to store data in most personal computers. DRAM stores each bit in a "cell" com- posed of a transistor and a capacitor. Because the capacitor in a DRAM cell can only hold a charge for a few milliseconds, DRAM must be continually refreshed, or rewritten, to retain its data.

e-mail (electronic mail)

Messages, usually text, sent from one person to another via computer. Can also be sent automatically to a group of addresses (mailing list).

slot covers

Metal plates that cover up unused expansion slots on the back of a PC. Useful in maintaining proper airflow through a computer case.

Hierarchical Directory Tree

Method by which Windows organizes files into a series of folders, called directories, under the root directory. (See also root directory.)

RAID (redundant array of inexpensive disks or redundant array of independent disks)

Method for creating a fault-tolerant storage system. RAID uses multiple hard drives in various configurations to offer differing levels of speed/data redundancy.

disk striping with parity

Method for providing fault tolerance by writing data across multiple drives and then including an additional drive, called a parity drive, that stores information to rebuild the data contained on the other drives. Requires at least three physical disks: two for the data and a third for the parity drive. This provides data redundancy at RAID levels 3-5 with different options.

MAC address filtering

Method of limiting wireless network access based on the physical, hard-wired address of the wireless NIC of a computing device.

Run as administrator

Method of running a Windows program with elevated privileges, disabling protections that normally limit a programs ability to damage the system.

CFS (Central File System)

Method to unify all storage devices within a network or organization to facilitate a single management point and to provide user access to any file or data within the organization.

Windows Update

Microsoft application used to keep Windows operating systems up to date with the latest patches or enhancements. (See Automatic Updates.)

IPSec (Internet Protocol Security)

Microsoft's encryption method of choice for networks consisting of multiple networks linked by a private connection, providing transparent encryption between the server and the client.

Windows Hardware Certification Program

Microsoft's rigorous testing program for hardware manufacturers, which hardware devices must pass before their drivers can be digitally signed.

page fault

Minor memory-addressing error.

brightness control

Mobile device feature controlling screen brightness. Can be set to automatically adjust to ambient light or be manually changed.

location services

Mobile device feature that can detect the device's location, enabling apps to request and use this information to provide location-aware services, such as finding nearby restaurants.

Wi-Fi calling

Mobile device feature that enables users to make voice calls over a Wi-Fi network, rather than a cellular network.

passcode lock

Mobile device security feature that requires you to type in a series of letters, numbers, or motion patterns to unlock the mobile device each time you press the power button.

e-reader

Mobile electronic device used for reading e-books

NFC (Near Field Communication)

Mobile technology that enables short-range wireless communication between mobile devices. Now used for mobile payment technology such as Apple Pay and Google Pay.

UEFI (Unified Extensible Firmware Interface)

Modern 32- or 64 bit firmware programming interface. Replaced the original 16-bit PC BIOS. UEFI supports large capacity storage drives, additional features, and a more direct booting process.

touch interface

Monitor with a type of sensing device (a digitizer) across its face that detects the location and duration of contact, usually by a finger or stylus.

S.M.A.R.T. (Self-Monitoring Analysis and Reporting Technology)

Monitoring system built into hard drives that tracks errors and error conditions within the drive.

Phillips head screwdriver

Most important part of a PC tech's toolkit

flatbed scanner

Most popular form of consumer scanner; runs a bright light along the length of the tray to capture an image.

FlexATX

Motherboard form factor. Motherboards built in accordance with the FlexATX form factor are very small, much smaller than microATX motherboards.

Inheritance

NTFS feature that passes on the same permissions in any subfolders/files resident in the original folder.

filename

Name assigned to a file when the file is first written on a disk. Every file on a disk within the same folder must have a unique name. Filenames can contain any character (including spaces), except the following: \ / : * ? " < > |

Ethernet

Name coined by Xerox for the first standard of network cabling and protocols. Based on a bus topology

DE (desktop environment)

Name for the various user interfaces found in Linux distributions.

Pentium

Name given to the fifth and later generations of Intel microprocessors; original had a 32-bit address bus, 64-bit external data bus, and dual pipelining. Also used for subsequent generations of Intel processors—the Pentium Pro, Pentium II, Pentium III, and Pentium 4. Currently used as a budget label for Intel CPUs.

Core

Name used for the family of Intel CPUs that succeeded the Pentium 4, such as the Core i3, Core i5, Core i7, and Core i9.

code names

Names that keep track of different variations within CPU models

Network File System (NFS)

Network file and print sharing protocol for UNIX and Linux systems that competed with Server Message Block (SMB). Usage has declined as SMV won out.

peer-to-peer network

Network in which each machine can act as both a client and a server.

Domain-Based Network

Network that eliminates the need for logging on to multiple servers by using domain controllers to hold the security database for all systems.

mail server

Networked host used to access e-mail messages

CSMA/CA (Carrier Sense Multiple Access/Collision Avoidance)

Networking scheme used by wireless devices to transmit data while avoiding data collisions, which wireless nodes have difficulty detecting.

cellular wireless networks

Networks that enable cell phones, smartphones, and other mobile devices to connect to the Internet.

Multiuser MIMO (MU-MIMO)

New version of MIMO included in 802.11ac that enables a WAP to broadcast to multiple users simultaneously.

hang time

Number of seconds a too-often-hung computer is airborne after you have thrown it out a second-story window.

binary numbers

Number system with a base of 2, unlike the number systems most of us use that have bases of 10 (decimal numbers), 12 (measurement in feet and inches), and 60 (time). Binary numbers are preferred for computers for precision and economy. An electronic circuit that can detect the difference between two states (on-off, 0-1) is easier and more inexpensive to build than one that could detect the differences among ten states (0-9).

grayscale depth

Number that defines how many shades of gray the scanner can save per dot.

multiboot installation

OS installation in which multiple operating systems are installed on a single machine.

toner (cartridge)

Object used to store the toner in a laser printer. (See also laser printer, toner.)

hang

Occurs when a computer or program stops responding to keyboard commands or other input; a computer or program in such a state is said to be 'hung'

component failure

Occurs when a system device fails due to a manufacturing or some other type of defect.

Fragmentation

Occurs when files and directories get jumbled on a fixed disk and are no longer contiguous. Can significantly slow down hard drive access times and can be repaired by using the defrag utility included with each version of Windows. (See also defragmentation.)

nbstat

Old command-line utility predating Windows. Provides information on NetBIOS. While not as useful as it once was, it can still help troubleshoot small workgroups.

su

Older Linux command for gaining root access.

TN (twisted nematic)

Older technology for LCD monitors. TN monitors pro- duce a decent display for a modest price, but they have limited viewing angles and can't accurately reproduce all the color information sent by the video card.

host (networking)

On a TCP/IP network, a single device that has an IP address- any device (usually a computer) that can be the source or destination of a data packet. In the mainframe world, computer thus is made available for use by multiple people simultaneously. Also, a virtualization, a computer running one or more virtual operating systems.

backside bus

On older CPUs, a set of wires that connected the CPU to Level 2 cache. First appeared in the Intel Pentium Pro.

frontside bus

On older PC architectures, the wires that connect the CPU to its external memory controller.

baud

One analog cycle on a telephone line. In the early days of telephone data transmission, the baud rate was often analogous to bits per second. Due to advanced modulation of baud cycles as well as data compression, this is no longer true.

Certified Cisco Network Associate (CCNA)

One of the certifications demonstrating a knowledge of Cisco networking products.

Personal Digital Assistant (PDA)

One of the earliest mobile devices. Lacked cellular connections and touch interfaces, but still shared basic features with current mobile devices.

NVIDIA Corporation

One of the foremost manufacturers of graphic cards and chipsets

CompactFlash (CF)

One of the oldest, physically largest but still popular flash media formats. Its interface uses a simplified PC Card bus, so it also supports I/O devices

command mode

One of the two modes in vi; it allows a user to perform any available text editing task that is not related to inserting text into the document.

insert mode

One of the two modes in vi; it allows the user to insert text into the document but does not allow any other functionality.

OpenGL

One of two popular APIs used today for video cards. Originally written for UNIX systems but now ported to Windows and Apple systems. (See also DirectX.)

POP3 (Post Office Protocol version 3)

One of two protocols that receive e-mail from SMTP servers. POP3 uses TCP port 110. While historically most e-mail clients used this protocol, the IMAP4 e-mail protocol is now more common.

storage pool

One or more physical drives grouped into a single Storage Space

theory of probable cause

One possible reason why something is not working; a guess.

mini connector

One type of power connector from a PC power supply unit. Supplies 5 and 12 volts to peripherals. Also known as a floppy connector.

Windows 10

Operating system developed by Microsoft that powers most desktop and portable computers in use today.

Windows 8/8.1

Operating system developed by Microsoft. Version of Windows noted for the Metro interface. Used for desktop and portable PCs and for mobile devices. Succeeded by Windows 10.

Windows Vista

Operating system developed by Microsoft. Version of Windows; came in many different editions for home and office use, but did not have a Server edition. Succeeded by Windows 7. No longer is supported.

Windows 7

Operating system developed by Microsoft. Version of Windows; comes in many different editions for home and office use, but does not have a Server edition. Succeeded by Windows 8/8.1.

macOS

Operating system from Apple that powers their desktop and portable computers. Based on UNIX; macOS runs on Intel/IBM-based hardware, just like Microsoft Windows. Before 2016, it was known as OS X.

image deployment

Operating system installation that uses a complete image of a hard drive as an installation media. Helpful when installing an operating system on a large number of identical PCs.

DVD (digital versatile disc)

Optical disc format that provides for 4-17 GB of video or data storage.

Blu-Ray Disc (BD)

Optical disc format that stores up to 100 GB of data, designed as a replacement media for DVD. Competed with HD DVD.

End Process Tree

Option in Task Manager to halt a program or background process and all of its supporting processes.

Last Known Good Configuration

Option on the Advanced Startup Options menu that enables your system to revert to a previous configuration to troubleshoot and repair any major system problems.

CD (compact disc)

Originally designed as the replacement for vinyl records, has become the primary method of long-term storage of music and data.

CMOS (complementary metal-oxide semiconductor)

Originally, computer systems had a standalone CMOS chip - a tiny bit RAM hooked up to a small battery that enabled it to hold system settings for the BIOS firmware even with the computer off. This has long since been incorporated into the chipset. CMOS is often informally used to refer to the CMOS setup program or system setup utility.

IDE (Integrated Drive Electronics)

PC specification for small- to medium-sized hard drives in which the controlling electronics for the drive are part of the drive itself, speeding up transfer rates and leaving only a simple adapter (or "paddle"). IDE only supported two drives per system of no more than 504 MB each, and has been completely supplanted by Enhanced IDE. EIDE supports four drives of over 8 GB each and more than doubles the transfer rate. The more common name for PATA drives. Also known as intelligent drive electronics. (See PATA.)

jumper

Pair of small pins that can be shorted with a shunt to configure many aspects of PCs. Often used in configurations that are rarely changed, such as master/slave settings on IDE drives.

SSID (Service Set Identifier)

Parameter used to define a wireless network; otherwise known as the network name.

jack (physical connection)

Part of a connector into which a plug is inserted. Also referred to as a port.

port (physical connection)

Part of a connector into which a plug is inserted. Physical ports are also referred to as jacks.

radio frequency

Part of the electromagnetic spectrum that is used for wireless broadcasting communication.

USB root hub

Part of the host controller that makes the physical connection to the USB ports.

HAL (hardware abstraction layer)

Part of the operating system that hides hardware differences from other parts of the operating system.

primary partition

Partition on a Windows hard drive that can store a bootable operating system.

Globally Unique Identifier Partition Table (GUID or GPT)

Partitioning scheme that enables you to create more than four primary partitions without needing to use dynamic disks.

virus shield

Passive monitoring of a computer's activity, checking for viruses only when certain events occur.

strong password

Password containing at least eight characters, including letters, numbers, and non-alphanumeric symbols

raster image

Pattern of dots representing what the final product should look like.

BitTorrent

Peer-to-peer file-sharing program.

maintenance

Periodic jobs that should be done to keep an operating system running well.

hardware

Physical computer equipment such as electrical, electronic, magnetic, and mechanical devices. Anything in the computer world that you can hold in your hand. A hard drive is hardware; Microsoft Word is not.

device charger

Plugs into a power source and charges a device through on of its ports, such as USB or Lightning. Convenient for charging while the device stays on.

optical mouse

Pointing device that uses light rather than electronic sensors to determine movement and direction the mouse is being moved.

trackball

Pointing device used in early portable computers, distinguished by a ball that is rolled with the fingers.

UTP (Unshielded Twisted Pair)

Popular type of cabling for telephone and networks, composed of pairs of wires twisted around each other at specific intervals. The twists serve to reduce interference (also called crosstalk). The more twists, the less interference. Unlike its cousin, STP, UTP cable has no metallic shielding to protect the wires from external interference. 1000BaseT uses UTP, as do many other networking technologies. UTP is available in a variety of grades, called categories, as follows: CAT 1 UTP Regular analog phone lines—not used for data communications. CAT 2 UTP Supports speeds up to 4 Mbps. CAT 3 UTP Supports speeds up to 16 Mbps. CAT 4 UTP Supports speeds up to 20 Mbps. CAT 5 UTP Supports speeds up to 100 Mbps. CAT 5e UTP Supports speeds up to 1000 Mbps. CAT 6 UTP Supports speeds up to 10 Gbps. CAT 6a UTP Supports speeds up to 10 Gbps. CAT 7 UTP Supports 10-Gbps networks at 100-meter segments; shielding for individual wire pairs reduces crosstalk and noise problems. CAT 7 is not a TIA /EIA standard.

camcorder

Portable device for recording audio and video. While camcorders originally recorded to tape (first analog, and later digital), most modern digital camcorders record to flash media.

external speaker

Portable device that can substantially improve on the audio output of a mobile device or portable computer. Typically connects via Bluetooth or a regular headphone jack.

hybrid (portable device)

Portable devices that stuff portable-computer power in mobile device-style form factors, such as a tablet.

virtual memory

Portion of the hard drive set aside by an OS to act like RAM when the system needs more RAM than is installed. A file containing this data is typically called page file in Windows and a swap file in UNIX platforms like Linux and macOS.

electromagnetic pulse (EMP)

Potentially damaging burst of electromagnetic energy caused by events such as electrostatic discharge (ESD), lightning, nuclear detonations, and so on.

sleep mode

Power management setting in which all data from RAM is preserved by powering down much of the computer but maintaining power to RAM, or by writing the contents of RAM to the mass storage drive before the system goes into a reduced-power mode. Upon waking up, the information is retrieved from the HDD or SSD and returned to RAM if necessary; the system continues where it left off.

throttling

Power reduction/thermal control capability allowing CPUs to slow down during low activity or high heat build-up situations. Intel's version is known as Speed- Step, AMD's as PowerNow!.

single rail

Power supply configuration where all power is supplied along a single pathway

robocopy

Powerful command-line utility for copying files and directories, even over a network.

subwoofer

Powerful speaker capable of producing extremely low-frequency sounds.

environmental control

Practice of protecting computing equipment from environmental damage by taking measures such as air conditioning, proper ventilation, air filtration, temperature monitoring, and humidity monitoring.

power plan

Preconfigured profiles (such as Balanced, High performance, and Power saver) in the Power Options applet that modify a Windows system's behavior to adjust power consumption.

giga

Prefix for the quantity of 1,073,741,824 (2^30) or for 1 billion. One gigabyte would be 1,073,741,824 bytes, except with hard drive labeling, where it means 1 billion bytes. One gigahertz is 1 billion hertz.

mega-

Prefix that stands for the binary quantity 1,048,576 (2^20) or the decimal quantity of 1,000,000. One megabyte is 1,048,576 bytes. One megahertz, however, is a million hertz. Sometimes shortened to Meg, as in "a 286 has an address space of 16 Megs."

tera-

Prefix that usually stands for the binary number 1,099,511,627,776 (240). When used for mass storage, it's often shorthand for 1 trillion bytes.

spoofing

Pretending to be someone or something else by placing false information into packets. Commonly spoofed data include a source MAC address or IP address, e-mail address, Web address, or user name. Generally a useful tool for enhancing or advancing other attacks, such as social engineering or spear fishing.

Port Forwarding

Preventing the passage of any IP packets through any ports other than the ones prescribed by the system administrator.

external data bus (EDB)

Primary data highway of all computers. Everything in your computer is tied either directly or indirectly to the external data bus. (See also frontside bus and backside bus.)

system BIOS

Primary set of BIOS stored on an EPROM or flash ROM chip on the motherboard. Defines the BIOS for all the assumed hardware on the motherboard, such as keyboard controller, floppy drive, basic video, and RAM.

PCL (Printer Command Language)

Printer language created by Hewlett-Packard to supersede simple ASCII codes and used on a broad cross section of printers. Identified as printer control language in CompTIA A+ exam objectives.

network printer

Printer that connects directly to a network.

dot-matrix printer

Printer that creates each character from an array of dots. Pins striking a ribbon against the paper, one pin for each dot position, form the dots. May be a serial printer (printing one character at a time) or a line printer.

dye-sublimation printer

Printer that uses a roll of heat-sensitive plastic film embedded with dyes, which are vaporized and then solidified onto specially coated paper to create a high-quality image.

thermal printer

Printer that uses heated printheads to create high-quality images on special or plain paper. Common in retail receipt printers, which use large rolls of thermal paper housed in a feed assembly that automatically draws the thermal receipt paper over the heating element.

heating element

Printing component of direct thermal printers. Burns dots into the surface of heat-sensitive thermal paper.

XML Paper Specification (XPS) Print path

Printing subsystem in Windows. Has enhanced color management and good print layout fidelity.

defragmentation (defrag)

Procedure in which all the files on a hard disk drive are rewritten on disk so that all parts of each file reside in contiguous clusters. The result is an improvement in disk speed during retrieval operations.

disk striping

Process by which data is spread among multiple (at least two) drives. Increases speed for both reads and writes of data. Considered RAID level 0 be- cause it does not provide fault tolerance.

disk mirroring

Process by which data is written simultaneously to two or more disk drives. Read and write speed is decreased but redundancy in case of catastrophe is increased.

firmware update

Process by which the BIOS of a motherboard can be updated to reflect patched bugs and added features. Performed usually, through CMOS, though some motherboard manufacturers provide a Windows program for performing a firmware update.

rooting

Process for circumventing the security restrictions and gaining access to the root user account on an Android device.

Jailbreaking

Process of making unauthorized modifications to operating systems and bypassing the DRM restrictions on Apple iPhones and iPads in order to run unapproved apps.

calibration

Process of matching the print output of a printer to the visual output of a monitor.

incident reporting

Process of reporting gathered data about a system or problem to supervisors. Creates a record of work accomplished, and may help identify patterns. Often documented on an incident report form.

multitasking

Process of running multiple programs or tasks on the same computer at the same time.

burn

Process of writing data to a writable optical disc, such as a DVD-R.

single sign-on (SSO)

Process that uses an account or credentials for a popular service (such as a Google account) to sign on or authenticate with other services.

autodetection

Process through which new disks are automatically recognized by the BIOS.

escalate

Process used when a person assigned to repair a problem is not able to get the job done, such as sending the problem to someone with more expertise.

pipeline

Processing methodology where multiple calculations take place simultaneously by being broken into a series of steps. Often used in CPUs and video processors.

hardware virtualization support

Processor features that speed up and simplify virtualization. Required for some hypervisors to function

Web Browser

Program designed to retrieve, interpret, and display Web pages.

CMOS setup program

Program enabling you to access and update CMOS data. Also referred to as the System Setup Utility or BIOS setup.

browser

Program specifically designed to retrieve, interpret, and display Web pages.

TWAIN (technology without an interesting name)

Programming interface that enables a graphics application, such as a desktop publishing program, to activate a scanner, frame grabber, or other image-capturing device.

Component Services

Programming tools in Windows for the sharing of data objects between programs.

CNR (communications and networking riser)

Proprietary slot used on some motherboards to provide a sound interference-free connection for modems, sound cards, and NICs.

Z-Wave

Proprietary wireless networking protocol (with an open API for programmers) designed to address home automation challenges.

system lockout

Protects against attempts to brute-force a lock screen or login system by locking the user out until they perform some more thorough authentication process. Occurs when too many consecutive login attempts fail.

Virtual Network Computing (VNC)

Protocol enabling remote desktop connections.

Service Location Protocol (SLP)

Protocol for advertising and discovering available services over a network. Most common with print devices. Uses TCP/UDP port 427.

IPv6 (Internet Protocol version 6)

Protocol in which addresses consist of eight sets of four hexadecimal numbers, each number being a value between 0000 and FFFF, using a colon to separate the numbers. Here's an example: FEDC:BA98:7654:3210:0800:200C:00CF:1234.

DHCP (Dynamic Host Configuration Protocol)

Protocol that enables client hosts to request and receive TCP/IP settings automatically from an appropriately configured server. Uses UDP ports 67 and 68.

IrDA (Infrared Data Association) protocol

Protocol that enables communication through infrared devices, with speeds of up to 4 Mbps.

NetBIOS (Network Basic Input/Output System)

Protocol that operates at the Session layer of the OSI seven-layer model. This protocol creates and manages connections based on the names of the computers involved. Uses TCP ports 137 and 139, and UDP ports 137 and 138.

Lightweight Directory Access Protocol (LDAP)

Protocol used by many operating systems and applications to access directories.

Remote Desktop Protocol (RDP)

Protocol used for Microsoft's Remote Desktop tool, Uses port 3389.

P4 power connector

Provides additional 12-volt power for the CPU to motherboards that support Pentium 4 and later processors

P1 power connector

Provides power to ATX motherboards; 20-pin with original ATX motherboards, 24-pin on current units.

power supply unit (PSU)

Provides the electrical power for a PC. Converts standard AC power into various voltages of DC electricity in a PC.

Unified Threat Management (UTM)

Providing robust network security by integrating traditional firewalls with many other security services such as IPS, VPN, load balancing, anti-malware, and more.

timbre

Qualities that differentiate the same note played on different instruments.

striped volume

RAID 0 volumes. Data is spread across two drives for increased speed.

double-sided RAM

RAM stick with RAM chips soldered to both sides of the stick. May only be used with motherboards designed to accept double-sided RAM. Very common.

ECC RAM/DRAM (error correction code DRAM)

RAM that uses special chips to detect and fix memory errors. Commonly used in high-end servers where data integrity is crucial.

unbuffered RAM

RAM without a register to act as a buffer between the DIMM and memory controller; in other words, normal, consumer grade RAM.

flash ROM

ROM technology that can be electrically reprogrammed while still in the PC. Overwhelmingly the most common storage medium of BIOS in computers today, as it can be upgraded without a need to open the computer on most systems.

RSA token

Random number generator used along with a user name and password to enhance security.

DMA controller

Resides between the RAM and the devices and handles DMA requests.

optical resolution

Resolution a scanner can achieve mechanically. Most scanners use software to enhance this ability.

native resolution

Resolution of an LCD monitor that matches the physical pixels on the screen.

data usage limit

Restrictions on how much data a user may consume. Once the user exceeds the limit, data may be blocked entirely or bandwidth may be throttled.

NTFS permissions

Restrictions that determine the amount of access given to a particular user on a system using NTFS.

USB Type-C (connector)

Reversible USB type cable that supports USB Super- Speed+ USB 3.1 with a top speed of 10 Gbps. Thunderbolt-enabled USB Type-C ports can reach top speeds of 40 Gbps.

NTFS (New Technology File System)

Robust and secure file system introduced by Microsoft with Windows NT. NTFS provides an amazing array of configuration options for user access and security. Users can be granted access to data on a file-by-file basis. NTFS enables object-level security, long filename support, compression, and encryption.

path

Route the operating system must follow to find an executable program stored in a subfolder.

Quality of Service (QoS)

Router feature used to prioritize access to network resources. Ensures certain users, applications, or services are prioritized when there isn't enough bandwidth to go around by limiting the bandwidth for certain types of data based on application protocol, the IP address of a computer, and all sorts of other features.

Port Triggering

Router function that enables a computer to open an incoming connection to one computer automatically based on a specific outgoing connection.

FTP (File Transfer Protocol)

Rules that enable two computers to talk to one another during a file transfer. Protocol used when you transfer a file from one computer to another across the Internet. FTP uses port numbers 20 and 21.

data storage

Saving a permanent copy of your work so that you can come back to it later.

data structure

Scheme that directs how an OS stores and retrieves data on and off a drive. Used interchangeably with the term file system. (See also file system.)

file system

Scheme that directs how an OS stores and retrieves data on and off a drive; FAT32 and NTFS are both file systems. Used interchangeably with the term "data structure." (See also data structure.)

monitor

Screen that displays data from a PC. Typically a flat-panel display, such as an LCD.

Level 2 (L2) cache

Second RAM cache accessed by the CPU. Much larger and often slower than the L1 cache, and accessed only if the requested program/data is not in the L1 cache.

NLX

Second form factor for slimline systems. Replaced the earlier LPX form factor. (NLX apparently stands for nothing; it's just a cool grouping of letters.)

partition

Section of the storage area for a hard disk. Created during initial preparation of the hard disk, before the disk is formatted.

logical drives

Sections of an extended partition on a hard drive that are formatted and (usually) assigned a drive letter, each of which is presented to the user as if it were a separate drive.

Partition Boot Sector

Sector of a partition that stores information important to its partition, such as the location of the OS boot files. Responsible for loading the OS on a partition.

HTTPS (HTTP over Secure Sockets Layer)

Secure form of HTTP used commonly for Internet business transactions or any time when a secure connection is required. Uses port 443. (See also HTTP.)

DirectX

Set of APIs enabling programs to control multimedia, such as sound, video, and graphics. Used in Windows Vista to draw the Aero desktop.

LoJack

Security feature included in some BIOS/UEFI that enables a user to track the location of a stolen PC, install a key logger, or remotely shut down the stolen computer.

SSL (Secure Sockets Layer)

Security protocol used by a browser to connect to secure Web sites. Replaced by Transport Layer Security (TLS).

bootstrap loader

Segment of code in a system's BIOS that scans for an operating system, looks specifically for a valid boot sector, and, when one is found, hands control over to the boot sector; then the bootstrap loader removes itself from memory.

on-demand

Self-service characteristic of cloud computing. Describes the customer's ability to set up, modify, and delete cloud resources (such as servers, storage, or databases) as needed.

rails

Separate DC voltage paths within an ATX power supply.

gearbox

Separate units or packages, also called gear packs, that combine multiple gears for performing mechanical functions in a printer. Most laser printers have two or three gearboxes that can be replaced individually if one fails.

eSATA

Serial ATA-based connector for external hard drives and optical drives.

COM ports

Serial communications ports available on a computer. COMx is used to designate a uniquely numbered COM port such as COM1, COM2, etc.

PCIe (PCI Express)

Serialized successor to PCI and AGP that uses the concept of individual data paths called lanes. May use any number of lanes, although a single lane (x1) and 16 lanes (x16) are the most common on motherboards.

SATA (serial ATA)

Serialized version of the ATA standard that offers many advantages over PATA (parallel ATA) technology, including thinner cabling, keyed connectors, and lower power requirements.

beep codes

Series of audible tones produced by a motherboard during the POST. These tones identify whether the POST has completed successfully or whether some piece of system hardware is not working properly. Consult the manual for your particular motherboard for a specific list of beep codes.

front-view projector

Shoots the image out the front and counts on you to put a screen in front at the proper distance.

patch cables

Short (2 to 5 feet) UTP cables that connect patch panels to a router or switch

worm

Similar to a virus, except that it is a program rather than a code segment hidden in a host program. A worm also copies itself automatically and actively transmits itself directly to other systems.

Duplexing

Similar to mirroring in that data is written to and read from two physical drives, for fault tolerance. Separate controllers are used for each drive, both for additional fault tolerance and for additional speed. Considered RAID level 1. Also called disk duplexing or drive duplexing.

cable lock

Simple anti-theft device for securing a laptop to a nearby object.

brute force

Simple attack that attempts to guess credentials to identify vulnerabilities by trying many possibilities.

clock cycle

Single charge to the clock wire of a CPU.

MFD (multifunction device)

Single device that consolidates functions from more than one document handling device such as a printer, copier, scanner, or fax machine.

software

Single group of programs designed to do a particular job; always stored on mass storage devices.

HDMI (High-Definition Multimedia Interface)

Single multimedia connection that includes both high-definition video and audio. One of the best connections for outputting to television. Also contains copy protection features.

laser

Single-wavelength, in-phase light source that is sometimes strapped to the head of sharks by bad guys. Note to henchmen: Lasers should never be used with sea bass, no matter how ill-tempered they might be.

throw

Size of the image a projector displays at a certain distance from the screen. Alternately, what you do with a computer that you just can't seem to get working.

ID badge

Small card or document for confirming the identity of its holder and what access they should be granted. May use built-in authentication tools such as RFID or smart card to function as a "something you have" authentication factor.

module

Small circuit board that DRAM chips are attached to. Also known as a "stick.

mini DIN

Small connection most commonly used for keyboards and mice. Many modern systems implement USB in place of mini-DIN connections. Also called PS/2.

ink cartridge

Small container of ink for inkjet printers.

wireless locator

Small device with signal lights to indicate the presence of Wi-Fi signals.

traces

Small electrical connections embedded in a circuit board.

power supply fan

Small fan located in a system power supply that draws warm air from inside the power supply and exhausts it to the outside.

recovery partition

Small hidden partition on a system's primary hard drive with a factory-fresh OS image to recover and reinstall from.

standoffs

Small mechanical separators that screw into a computer case. A motherboard is then placed on top of the standoffs, and small screws are used to secure it to the standoffs.

context menu

Small menu brought up by right-clicking on objects in Windows

texture

Small picture that is tiled over and over again on walls, floors, and other surfaces to create a 3-D world.

patch

Small piece of software released by a software manufacturer to correct a flaw or problem with a particular piece of software.

connector

Small receptacle used to attach a cable to a device or system. Common types of connector include USB, PS/2, RJ-45, VGA, HDMI, DVI, HD15, DisplayPort, and Thunderbolt.

satellite latency

Small signal delay caused by the distance travelled by satellite signals.

Liquid Contact Indicators (LCIs)

Small sticker that permanently changes color after getting wet, often from white to red. Installed at various locations inside mobile and portable devices.

PAN (Personal Area Network)

Small wireless network created with Bluetooth technology and intended to link computers and other peripheral devices.

mini-USB

Smaller USB connector often found on digital cameras.

thread

Smallest logical division of a single program.

mobile payment service

Smartphone feature that can use a connected bank account to automatically transfer payments to merchants. May work in conjunction with Near Field Communication (NFC).

Disk Management

Snap-in available with the Microsoft Management Console that enables techs to configure the various disks installed in a system; available in the Computer Management Administrative Tool.

telephone scams

Social engineering attack in which the attacker makes a phone call to someone in an organization to gain information.

ZIF (zero insertion force) socket

Socket for CPUs that enables insertion of a chip without the need to apply pressure. Intel promoted this socket with its overdrive upgrades. The chip drops effortlessly into the socket's holes, and a small lever locks it in.

virtual NIC

Software network interface for a virtual machine. For access to a broader network than the host system is connected to, the virtual NIC needs to be bridged to the host's physical NIC. This enables the virtual NIC to receive an address from DHCP, just like a physical NIC.

emulator

Software or hardware that converts the commands to and from the host machine into an entirely different platform.

codec (compressor/decompressor)

Software that compresses or decompresses media streams.

terminal emulation

Software that enables a PC to communicate with another computer or network as if it were a specific type of hardware terminal.

Hypervisor

Software that enables a single computer to run multiple operating systems simultaneously.

proxy server

Software that enables multiple connections to the Internet to go through one protected computer. Common security feature in the corporate world. Applications that want to access Internet resources send requests to the proxy server instead of trying to access the Internet directly, which both protects the client computers and enables the network administrator to monitor and restrict Internet access.

freeware

Software that is given away free of charge, but whose author still retains all rights.

virtual printer

Software that presents itself as a printer, but does something else rather than just print the document, such as saving it to a given file type.

spyware

Software that runs in the background of a user's PC, sending information about browsing habits back to the company that installed it onto the system.

network protocol

Software that takes the incoming data received by the network card, keeps it organized, sends it to the application that needs it, and then takes outgoing data from the application and hands it to the NIC to be sent out over the network.

SDK (software development kit)

Software that used to create custom applications or add features to existing applications on your mobile device.

DUN (Dial-up Networking)

Software used by Windows to govern the connection between the modem and the ISP.

open source software

Software whose source code is made available to the public, enabling anyone to copy, modify, and redistribute the source code without paying royalties or fees.

keylogger

Software, usually malware, that copies, saves, and sometimes uploads all keystrokes and other inputs on a computer. Keyloggers are used gather information such as passwords, sites visited, and other activities performed on a computer.

LED (light-emitting diode)

Solid-state device that vibrates at luminous frequencies when current is applied.

PC tech

Someone with computer skills who works on computers.

PCM (pulse code modulation)

Sound format developed in the 1960s to carry telephone calls over the first digital lines.

plenum

Space in the ceiling, walls, and floor where special plenum-grade (fire-retardant) network cables can be run out of sight.

ownership permission

Special NTFS permissions granted to the account that owns a file or folder. Owners can do anything they want to the files and folders they own, including changing their permissions.

riser card

Special adapter card, usually inserted into a special slot on a motherboard, that changes the orientation of expansion cards relative to the motherboard. Riser cards are used extensively in slimline computers to keep total depth and height of the system to a minimum. Sometimes called a daughterboard.

cache (disk)

Special area of RAM that stores the data most frequently accessed from the hard drive. Cache memory can optimize the use of your systems.

dynamic disks

Special feature of Windows that enables users to span a single volume across two or more drives. Dynamic disks do not have partitions; they have volumes. Dynamic disks can be striped, mirrored, and striped or mirrored with parity.

CDDA (CD-Digital Audio)

Special format used for early CD-ROMs and all audio CDs; divides data into variable-length tracks. A good format to use for audio tracks but terrible for data because of lack of error checking.

thermal paper

Special heat-sensitive paper for use in thermal printers.

function (Fn) key

Special key on many laptops that enables some keys to perform a third duty.

swap partition

Special partition found on Linux and UNIX systems that behaves like RAM when your system needs more RAM than is installed.

Take Ownership

Special permission allowing users to seize control of a file or folder and potentially prevent others from accessing the file/folder.

power saving modes

Special power modes that limit or modify device functionality in order to prolong battery life. May take steps such as disabling communications, reducing processor speed, limiting programs, and dimming the screen.

cache (L1, L2, L3, etc.)

Special section of fast memory, usually built into the CPU, used by the onboard logic to store information most frequently accessed by the CPU.

ECC (error-correcting code)

Special software, embedded on hard drives, that constantly scans the drives for bad blocks.

loopback test

Special test to confirm a NIC can send and receive data. A full external loopback test requires a loopback plug inserted into the NICs port.

DVI (Digital Visual Interface)

Special video connector designed for digital to- digital connections; most commonly seen on PC video cards and LCD monitors. Some versions also support analog signals with a special adapter.

Mini-PCI

Specialized form of PCI designed for use in laptops.

troubleshooting methodology

Steps a technician uses to solve a problem. CompTIA A+ defines six steps: identify the problem; establish a theory of probable cause (question the obvious); test the theory to determine cause; establish a plan of action to resolve the problem and implement a solution; verify the full system functionality and, if applicable, implement preventive measures; and document findings, actions, and outcomes.

parity space

Storage Space that adds resiliency similar to RAID 5 or RAID 6.

mirror space

Storage Space that mirrors files across two or more drives, like RAID 1 or RAID 10.

register

Storage area inside the CPU used by the onboard logic to perform calculations. CPUs have many registers to perform different functions.

magnetic hard drives

Storage devices that read and write data encoded magnetically onto spinning aluminum platters

EFS (Encrypting File System)

Storage organization and management service, such as NTFS, that has the capability of applying a cipher process to the stored data.

Simple space

Storage space that just pools storage space, like JBOD.

partition boot sector

Stores information for booting from the partition, such as the location of OS boot files

untrusted source

Stores or sites where apps can be obtained outside of the legitimate trusted sources run by major vendors.

CAT 7

Supports 10-Gbps networks at 100-meter segments; shielding for individual wire pairs reduces crosstalk and noise problems. CAT 7 is not a TIA/EIA standard.

interrupt/interruption

Suspension of a process, such as the execution of a computer program, caused by an event external to the computer and performed in such a way that the process can be resumed. Events of this kind include sensors monitoring laboratory equipment or a user pressing an interrupt key.

object

System component that is given a set of characteristics and can be managed by the operating system as a single entry.

environment variables

System data such as the date and time, currently logged-in users, running operating system version, and more. Scripts and programs on a system often use these variables to tailor their behavior to the system's capabilities and configuration.

WWW (World Wide Web)

System of Internet servers that supports documents formatted in HTML and related protocols. Can be accessed by applications that use HTTP and HTTPS, such as Web browsers.

data classification

System of organizing data according to its sensitivity. Common classifications include public, highly confidential, and top secret.

DLP (Data Loss Prevention)

System or set of rules designed to stop leakage of sensitive information. Usually applied to Internet appliances to monitor outgoing network traffic.

DNS (Domain Name Service)

TCP/IP name resolution system that translates a host name into an IP address. Uses UDP port 53.

startup

Tab added to Task Manager in Windows 8 that allows a user to control which programs start with Windows and see what impact they are having on load time

Details

Tab added to the Task Manager in Windows 8 to collect much of the detail from the older Processes tab, including executable names, PIDs, status, executing user, a description, and present resource use. Many more columns can be enabled as well.

Processes

Tab in Task Manager that lists all running processes on a system. Frequently a handy tool for ending buggy or unresponsive processes.

Users

Tab in Task Manager that shows other logged-in users and enables you to log off other users if you have the proper permissions. Starting in Windows 8, also includes information on resources consumed by programs the user is running.

Performance

Tab in Task Manager that tracks PC performance, including CPU usage, available physical memory, size of the disk cache, and other details about memory and processes.

System Protection

Tab in Windows System Properties dialog box that enables you to configure how and when the system will create restore points and provides easy access to existing restore points via System Restore.

partition table

Table located in the boot sector of a hard drive that lists every partition on the disk that contains a valid operating system.

drive cloning

Taking a PC and making a duplicate of the hard drive, including all data, software, and configuration files, and transferring it to another PC.

memory addressing

Taking memory address from system RAM and using it to address non-system RAM or ROM so the CPU can access it.

Networking

Task Manager tab in Windows 7 (merged into the Performance tab in Windows 8), which shows activity on current network connections.

Mobile Device Management (MDM) policies

Technical controls that govern how mobile devices are used as tools in the workplace.

lithium polymer (LiPo)

Technically, a variant of Li-Ion batteries that use a solid, polymer electrolyte. In practice, this term is commonly applied to traditional Li-Ion batteries packed in polymer bags.

DMA (Direct Memory Access)

Technique that some PC hardware devices use to transfer data to and from the memory without using the CPU.

biometric authentication

Technology for authenticating system users that compares a person's unique characteristics such as fingerprints, face, or retinal image, against a stored set profile of these characteristics.

Scalable Link Interface (SLI)

Technology for connecting two or more NVIDIA GPUs together in a system.

DTS (Digital Theatre Systems)

Technology for sound reductions and channeling methods, similar to Dolby Digital.

NX bit

Technology that enables the CPU to protect certain sections of memory. This feature, coupled with implementation by the operating system, stops malicious attacks from getting to essential operating system files. Microsoft calls the feature Data Execution Prevention (DEP), turned on by default in every OS.

face lock

Technology that enables use of facial features to unlock a mobile device or personal computer.

Power over Ethernet (PoE)

Technology that provides power and data transmission through a single network cable.

REt (Resolution Enhancement technology)

Technology that uses small dots to smooth out jagged edges that are typical of printers without RET, producing a higher-quality print job.

proprietary

Technology unique to a particular vendor.

S/MIME (Secure/Multipurpose Internet Mail Extensions)

Technology used to configure digital signature settings for e-mail, and contacts for a corporate address book, depending on how the corporate e-mail server is set up.

Color Depth (scanner)

Term to define a scanner's ability to produce color, hue, and shade.

SSH (Secure Shell)

Terminal emulation program similar to Telnet, except that the entire connection is encrypted. Uses port 22.

force stop

Terminate an Android app and all associated background processes. More extreme than simply closing the app, which may leave background processes running.

command prompt

Text prompt for entering commands

kernel panic

The Linux equivalent of the BSoD. An error from which the OS can't recover without a reboot.

SMTP (Simple Mail Transfer Protocol)

The main protocol used to send electronic mail from server to server on the Internet. Uses port 25.

gpresult

The Windows command to find out group policies that are currently applied to a system for the computer or user.

Registry Editor

The Windows utility used to edit the Windows registry.

remotely wipe

The ability to remotely delete the user data from a mobile device that has been lost or stolen.

dumpster diving

The act of digging through trash receptacles to find information that can be useful in an attack.

tethering

The act of using a cellular-network-connected mobile device as a mobile hotspot.

hostID

The address of a TCP/IP device such as a computer, printer, camera, or other device.

potential

The amount of electrical energy stored in an object.

Lumens

The amount of light given off by a light source from a certain angle that is perceived by the human eye. Unit of measure for amount of brightness on a projector or other light source.

response rate

The amount of time it takes for all the sub-pixels on an LCD panel to change from one state to another. This change is measured in one of two ways: black to white (BtW) measures how long it takes the pixels to go from pure black to pure white and back again, and gray to gray (GtG) measures how long it takes the pixels to go from one gray state to another.

CPU (Central Processing Unit)

The brain of the computer, the CPU performs the arithmetic, logical, and input/output operations of the system.

tiles

The building blocks of Windows 8's Modern UI, as potentially "smart" app shortcuts, capable of displaying dynamic and changing information without even opening the app.

bandwidth

The capacity of a network to transmit a given amount of data during a given period.

clock speed

The maximum number of clock cycles that a CPU can handle in a given period of time, measured in MHz or GHz.

segment

The connection between a computer and a switch.

working directory

The current directory used by command-line commands unless they explicitly specify a target file or directory. The prompt usually indicates the working directory.

home screen

The default "desktop" of a mobile device.

soft reset

The equivalent of a reboot or restart for a mobile device. An important troubleshooting step because it clears running programs from memory and restarts the operating system. Some portable devices that closely resemble mobile devices may also use soft resets.

processing (printing)

The first step of the laser printing process, in which the printer translates incoming print commands into pages rendered for printing.

ExpressCard

The high-performance serial version of the PC Card that replaced PC Card slots on laptop PCs over the past decade. ExpressCard comes in two widths: 34 mm and 54 mm, called ExpressCard/34 and ExpressCard/54.

Windows Preinstallation Environment (Windows PE)

The installation program for Windows.

Mini-ITX

The largest and the most popular of the three ITX form factors. At a miniscule 6.7 by 6.7 inches, Mini-ITX competes with microATX and proprietary small form factor (SFF) motherboards.

CMOS battery

The lithium coin-cell battery on the motherboard used to power the CMOS chip that holds BIOS setup data so that the data is retained when the computer is unplugged.

Charms bar

The location in Windows 8 and 8.1 of the charms tools. Accessed by moving the cursor to the upper-right corner of the screen.

Mini Secure Digital (MiniSD)

The medium-sized form factor of the SD flash memory standard.

mv

The move command in Linux and macOS.

SATA Express (SATAe)

The newest version of SATA that ties capable drives directly into the PCI Express bus on motherboards. Each lane of PCIe 3.0 is capable of handling up to 8 Gbps data throughput. A SATAe drive grabbing two lanes, therefore, could move a whopping 16 Gbps through the bus.

Color Depth (Display)

The number of bits necessary to represent the number of colors in graphics mode. Common color bit depths are 16-bit and 32-bit, representing 65,536 colors and 16.7 million colors (plus an 8-bit alpha channel for transparency levels), respectively.

IP address

The numeric address of a computer connected to a TCP/IP network, such as the Internet. IPv4 addresses are 32 bits long, written as four octets of 8-bit binary. IPv6 addresses are 128 bits long, written as eight sets of four hexadecimal characters. IP addresses must be matched with a valid subnet mask, which identifies the part of the IP address that is the network ID and the part that is the host ID.

iOS

The operating system used on the iPhone, iPod Touch, and iPad.

RAID 10

The opposite of RAID 0+1, two mirrored RAID 0 configurations. Also provides both speed and redundancy, and also requires four disks.

Metro UI

The original name for the Windows 8 user interface. Due to legal concerns, it was rebranded the "Modern UI."

%SystemRoot%

The path where the operating system is installed.

bus

The paths, or lines, on the motherboard on which data, instructions, and electrical power move from component to component. Also a network topology where computers all connect to a main line called a bus cable.

color space

The portion of all possible colors that a device (such as LCD display or camera) is able to display or save.

Backup Testing

The process of ensuring that file or system backups have produced backups from which you can restore usable systems and files.

sync

The process of keeping files on mobile devices up to date with the versions on desktop computers or over the Internet.

patch management

The process of keeping software updated in a safe and timely fashion

Formatting

The process of preparing a partition to store files by creating a file system to organize the blocks and creating a root directory.

salting

The process of protecting password hashes from being easily reversed with a rainbow table by adding additional values to each password before hashing and storing it.

ISDN (integrated services digital network)

The process of sending telephone transmission across fully digital lines end-to-end, replacing the analog telephone system. ISDN is superior to POTS telephone lines because it supports a transfer rate of up to 128 Kbps for sending information from computer to computer. It also allows data and voice to share a common phone line. DSL reduced demand for ISDN substantially.

Authorization

The process that defines what resources an authenticated user may access and what he or she may do with those resources.

syntax (command)

The proper way to write a command-line command so that it functions and does what it's supposed to do.

processing (computing)

The second step of the computing process, where the CPU completes the tasks that the user's input has given.

Micro Secure Digital (MicroSD)

The smallest form factor of the SD flash memory standard. Often used in mobile devices.

host (virtualization)

The system running (or hosting) a virtual machine.

digitizer (screen)

The touchscreen overlay technology that converts finger and stylus contact into input data for the device to use.

CRT (cathode ray tube)

The tube of a monitor in which rays of electrons are beamed onto a phosphorescent screen to produce images. Also a shorthand way to describe a monitor that uses CRT rather than LCD technology.

U (units)

The unique height measurement used with equipment racks; 1 U equals 1.75 inches. A 1U device fits in a 1.75 inch space, a 2U device fits in a 3.5 inch space, and a 4U device fits in a 7inch space.

subnet mask

The value used in TCP/IP settings to divide the IP address of a host into its component parts: network ID and host ID.

electric potential

The voltage differential between any two objects, one of which is frequently ground or earth, resulting in a degree of attraction for the electrons to move from one of the objects to the other. A large difference between a person and a doorknob, for example, can lead to a shocking experience when the two touch.

topology

The way computers connect to each other in a network.

transfer corona

Thin wire, usually protected by other thin wires, that applies a positive charge to the paper during the laser printing process, drawing the negatively charged toner particles off of the drum and onto the paper. Newer printers accomplish the same feat using a transfer roller that draws the toner onto the paper.

Ultrabook

Thin, powerful laptop powered by Intel processors and built according to the Intel design specification. Competes directly with the Apple Mac Air.

Authentication Factor

Things used for authentication, such as something you know, something you have, or something you are. Authentication involves one or more of these factors and can, therefore, be one-factor, two-factor, or three-factor authentication.

Level 3 (L3) cache

Third RAM cache accessed by the CPU. Much larger and slower than the L1 and L2 caches, and accessed only if the requested program/data is not in the L2 cache.

net use

This subcommand of the Windows net command enables a user to connect, disconnect, and view the information about existing connections to network resources.

net user

This subcommand of the Windows net command enables a user to create, delete, and change user accounts.

refresh rate

Time required for a monitor to redraw the whole screen

MBR (Master Boot Record)

Tiny bit of code that takes control of the boot process from the system BIOS.

shunt

Tiny connector of metal enclosed in plastic that creates an electrical connection between two posts of a jumper.

sub-pixels

Tiny liquid crystal molecules arranged in rows and columns between polarizing filters used in LCDs.

debug

To detect, trace, and eliminate errors in computer programs.

boot

To initiate an automatic routine that clears the memory, loads the operating system, and prepares the computer for use. Term is derived from "pull yourself up by your bootstraps." Computers must do that because RAM doesn't retain program instructions when power is turned off. A cold boot occurs when the PC is physically switched on. A warm boot loads a fresh OS without turning off the computer, lessening the strain on the electronic circuitry. To do a warm boot, press the ctrl-alt-delete keys twice in rapid succession (the three-fingered salute).

cluster

To overcome some limitations in addressing inherent in each file system, Windows file systems organize data into groups called clusters. Cluster size varies by file system devices and users.

decrypt

To pass decryption keys and encrypted data through the appropriate decryption algorithm in order to retrieve the original unencrypted data.

Identify the problem

To question the user and find out what has been changed recently or is no longer working properly. Step 1 of 6 in the CompTIA troubleshooting theory

overclocking

To run a CPU or video processor faster than its rated speed.

Local Users and Groups

Tool enabling creation and changing of group memberships and accounts for users.

Performance Options

Tool enabling users to configure CPU, RAM, and virtual memory settings.

Display applet

Tool in Windows XP and Windows 7 used to adjust display settings, including resolution, refresh rate, driver information, and color depth.

shell

Tool that interprets command-line input, also known as the command-line interpreter.

NetBoot

Tool that makes it easy to install, upgrade, and manage macOS on many remote systems at once, over a network

tech toolkit

Tools a PC tech should never be without, including a Phillips-head screwdriver, a pair of tweezers, a flat-head screwdriver, a hemostat, a Torx wrench, a parts retriever, and a nut driver or two.

bank

Total number of SIMMs or DIMMs that can be accessed simultaneously by the chipset. The "width" of the external data bus divided by the "width" of the SIMM or DIMM sticks. DIMM slots that must be populated to activate dual, triple or quad channel memory.

tap

Touchscreen gesture where you press a spot on the screen to start an app or interact with a running app.

laptop

Traditional clamshell portable computing device with built-in LCD monitor, keyboard, and trackpad.

stripe set

Two or more drives in a group that are used for a striped volume.

satellites

Two or more standard stereo speakers to be combined with a subwoofer for a speaker system (i.e., 2.1, 5.1, 7.1, etc.).

file extension

Two, three, four, five or more letters that follow a filename and identify the type of file (file format). Common file extensions are .zip, .exe, .doc, .java, and .xhtml.

DDR SDRAM (double data rate SDRAM)

Type of DRAM that makes two processes for every clock cycle. (See also DRAM.)

TFT (thin film transistor)

Type of LCD screen. (See also active matrix.)

DDR4 SDRAM

Type of SDRAM that offers higher density and lower voltages than DDR3, and can handle faster data transfer rates. Maximum theoretical capacity of DDR4 DIMMs is up to 512 GB.

DDR2 SDRAM

Type of SDRAM that sends 4 bits of data in every clock cycle. (See also DDR SDRAM.)

DDR3 SDRAM

Type of SDRAM that transfers data at twice the rate of DDR2 SDRAM.

fingerprint lock

Type of biometric device that enables a user to unlock a mobile device using a fingerprint.

disk duplexing

Type of disk mirroring using two separate controllers rather than one; faster than traditional mirroring.

LCD (liquid crystal display)

Type of display commonly used on portable computers. LCDs have also replaced CRTs as the display of choice for desktop computer users. LCDs use liquid crystals and electricity to produce images on the screen.

DC (direct current)

Type of electricity in which the flow of electrons is in a complete circle in one direction.

single-mode fiber optic cabling

Type of fiber optic cabling that uses laser light to transmit at very high rates over long distances. Still fairly rare.

LC

Type of fiber optic connector.

SC

Type of fiber optic connector.

ST

Type of fiber optic connector.

multimode

Type of fiber-optic cabling capable of transmitting multiple light signals at the same time using different reflection angles within the cable core. Signals tend to degrade over distance, limiting multimode cable to short distances.

extended partition

Type of nonbootable hard disk partition. May only have one extended partition per disk. Purpose is to divide a large disk into smaller partitions, each with a separate drive letter.

dual-voltage

Type of power supply that works with either 110- or 220-volt outlets.

M.2

Type of space efficient expansion slot common in recent portable computers. Formerly known as Next Generation Form Factor (NGFF). Also found on desktop motherboards. While M.2 is a general expansion slot supporting devices such as Wi-Fi cards, its often used to install an NVMe SSD.

optical disc/media

Types of data discs (such as DVDs, CDs, BDs, etc.) that are read by a laser.

TV tuner

Typically an add-on device that allows users to watch television on a computer.

ls

UNIX equivalent of the dir command, which displays the contents of a directory.

SuperSpeed USB 10 Gbps

USB 3.1 Gen 2 at 10 Gbps

micro-USB

USB connector commonly found on a variety of devices including Android phones. Slowly being replaced by USB Type-C connectors (especially in Android phones).

Low-Speed USB

USB standard that runs at 1.5 Mbps. Also called USB 1.1.

Full-Speed USB

USB standard that runs at 12 Mbps. Also known as USB 1.1.

Hi-Speed USB

USB standard that runs at 480 Mbps. Also referred to as USB 2.0.

RJ (registered jack) connector

UTP cable connector, used for both telephone and network connections. RJ-11 is a connector for four-wire UTP; usually found in telephone connections. RJ-45 is a connector for eight-wire UTP; usually found in network connections.

BNC

Uncommon coax connector secured with a quarter twist.

electrostatic discharge (ESD)

Uncontrolled rush of electrons from one object to another. A real menace to PCs, as it can cause permanent damage to semiconductors.

drive-by download

Undesired file downloads generated by turpid Web sites and ads.

scan code

Unique code corresponding to each key on the keyboard, sent from the keyboard controller to the CPU.

SID (security identifier)

Unique identifier for every PC that most techs change when cloning

SCSI ID

Unique identifier used by SCSI devices. No two SCSI devices may have the same SCSI ID.

byte

Unit of 8 bits; fundamental data unit of personal computers. Storing the equivalent of one character, the byte is also the basic unit of measurement for computer storage.

Print to PDF

Using a virtual printer that produces a PDF file you can save, instead of sending the document to a physical printer

Stateful Packet Inspection (SPI)

Used by hardware firewalls to inspect each incoming packet individually for purposes such as blocking traffic that isn't in response to outgoing requests.

channel

Used in a common method for numbering boot devices; the first boot device is channel 1, the second 2, and so on.

vertices

Used in the second generation of 3-D rendering; have a defined X, Y, and Z position in a 3-D world.

counter

Used to track data about a particular object when using Performance Monitor.

power good wire

Used to wake up the CPU after the power supply has tested for proper voltage.

Standard user account

User account in Windows that has limited access to a system. Accounts of this type cannot alter system files, cannot install new programs, and cannot edit some settings by using the Control Panel without supplying an administrator passwords.

effective permissions

User's combined permissions granted by multiple groups.

Desktop

User's primary interface to the Windows operating system.

default user accounts/groups

Users or groups that are enabled by default. Some such as the guest account, represent a security risk.

RAID 5

Uses block-level and parity data striping. Requires three or more drives.

RAID 0

Uses byte-level striping and provides no fault tolerance.

inkjet printer

Uses liquid ink, sprayed through a series of tiny jets, to print text or images on a piece of paper.

RAID 1

Uses mirroring or duplexing for increased data redundancy.

impact printer

Uses pins and inked ribbons to print text or images on a piece of paper. Impact printers can make use of a few special types of paper. Tractor-feed paper has holes so that printers with sprockets can continuously print massive stacks of the stuff. Special multi-part impact paper can be used tp print receipts in duplicate, triplicate, or more.

client-side virtualization

Using a hypervisor installed on a client machine to run a virtual machine. The VM may be created and stored on the client machine or accessed over the network.

geofencing

Using a mobile device's GPS to define geographical boundaries where an app can be used.

multicore processing

Using two or more execution cores on one CPU die to divide up work independently of the OS.

registration (product)

Usually optional process that identifies the legal owner/use of the product to the supplier.

buffered/registered RAM

Usually seen in motherboards supporting more than four sticks of RAM; used to address interference issues caused by the additional sticks. It accomplishes this with a small register installed on some memory modules to act as a buffer between the DIMM and the memory controller.

snap-ins

Utilities that can be used with the Microsoft Management Console.

Event Viewer

Utility made available in Windows as an MMC snap-in that enables users to monitor various system events, including network bandwidth usage and CPU utilization.

Device Manager

Utility that enables techs to examine and configure all the hardware and drivers in a Windows PC.

motherboard book

Valuable resource when installing a new motherboard. Normally lists all the specifications about a motherboard, including the type of memory and type of CPU usable with the motherboard.

checksum

Value generated from some data, like a file, and saved for comparing to other checksums later. Can be used to identify identical data, such as files on a user's system that match known viruses. Checksums can also be used to monitor whether a program is changing itself over time, which is a strong warning sign that it may be malware that evolves to avoid detection.

nit

Value used to measure the brightness of an LCD display. A typical LCD display has a brightness of between 100 and 400 nits.

gaming laptop

Variant of the desktop-replacement laptop designed to play resource-hungry games on the go, often at a high price.

microATX

Variation of the ATX form factor, which uses the ATX power supply. MicroATX motherboards are generally smaller than their ATX counterparts but retain all the same functionality.

Windows XP

Version of Windows that replaced both the entire Windows 9x line and Windows 2000; does not have a Server version. No longer supported by Microsoft. Succeeded by Windows Vista.

SRAM (Static RAM)

Very high speed RAM built into the CPUs that reduces wait states by preloading as many instructions as possible and keeping copies of already run instructions and data in case the CPU needs to work on them again.

guest account

Very limited built-in account type for Windows; a member of the Guest group.

SD (Secure Digital)

Very popular format for flash media cards; also supports I/O devices.

xD (Extreme Digital) picture card

Very small flash media card format.

interpolation

Video capture and display technology that calculates the color value and light intensity between pixels to fill the information that is not directly captured or saved.

XGA (extended graphics array)

Video display mode of 1024 × 768.

SXGA

Video display mode of 1280 × 1024.

WUXGA

Video display mode of 1920 × 1200.

SVGA (super video graphics array)

Video display mode of 800 x 600. Native SVGA displays are rare these days, but Windows might go into SVGA mode if the video driver is corrupt.

WXGA

Video display mode. Most often of 1366 x 768, though a variety of similar resolutions are also known as WXGA.

high dynamic range (HDR)

Video technology that increases the bandwidth of display colors and light intensity above standard dynamic range.

snapshot

Virtualization feature that enables you to save an extra copy of the virtual machine as it is exactly at the moment the snapshot is taken.

polymorphic virus

Virus that attempts to change its signature to prevent detection by antivirus programs, usually by continually scrambling a bit of useless code. Often shortened to polymorph.

stealth virus

Virus that uses various methods to hide from antivirus software

User Interface

Visual representation of the computer on the monitor that makes sense to the people using the computer, through which the user can interact with the computer. This can be a graphical user interface (GUI) like Windows 7 or a command line interface like the Windows PowerShell or the Recovery Console.

virtual assistant

Voice-activated technology that responds to user requests for information. Virtual assistants can be used to search the Internet, make reminders, do calculations, and launch apps.

simple volume

Volume created when setting up dynamic disks. Acts like a primary partition on a dynamic disk.

mirrored volume

Volume that is mirrored on another volume. (See also mirroring.)

spanned volume

Volume that uses space on multiple dynamic disks.

roaming

When a mobile device connects to different carriers' networks other than the home carrier. Sorts them by the Preferred Roaming List (PRL)

parallel execution

When a multicore CPU processes more than one thread.

replication

When a virus makes copies of itself, often by injecting itself into other executables.

viewing angle

Width (measured from the center to the side of a display) range within which the image can be fully seen.

Start screen

Windows 10 version of the start menu, which functions as a combination of the traditional Start menu and the Windows 8/8.1 Modern UI

Windows Explorer

Windows 7 - utility that enables you to manipulate files and folders stored on the drives in your computer.

System Tools

Windows 7 menu containing tools such as System Information and Disk Defragmenter, accessed by selecting Start | All Programs | Accessories | System Tools.

Task Scheduler

Windows 7 utility enabling users to set tasks to run automatically at certain times.

navigation pane

Windows 7's name for the Folders list in Windows Explorer.

Windows Easy Transfer

Windows 7/8/8.1 method of transferring user data and personalization settings to a new PC. It is not available in Windows 10.

bootmgr

Windows Boot Manager for Vista and later versions. Manages the boot process using information from the Boot Configuration Data (BCD) file.

Power Options

Windows Control Panel applet that enables better control over power use by customizing a Balanced, Power saver, or High-performance power plan.

Programs and Features

Windows Control Panel applet; enables uninstalling or changing program options and altering Windows features.

Reset your PC

Windows RE option in Windows 8/8.1 and later that nukes the system— deleting all apps, programs, user files, and user settings—and presents a fresh installation of Windows. Use Reset as the last resort when troubleshooting a PC. And back up data first, if possible.

Refresh your PC

Windows RE option in Windows 8/8.1 that rebuilds the OS, but preserves all user files and settings and any applications purchased from the Windows Store. Note well: Refresh deletes every other application on a system. Renamed Keep my Files in Windows 10.

remove everything

Windows Recovery Environment option in Windows 10 that deletes all apps, programs, user files, and user settings - resulting in a fresh installation of Windows. Use as a last resort when troubleshooting (and back up data first).

Keep my files

Windows Recovery Environment option in Windows 10 that rebuilds the OS, but preserves user files, settings, and Microsoft Store applications (while deleting all other applications on the system).

shutdown

Windows and Linux command-line for shutting down the computer.

hostname

Windows command for displaying the name of a computer

gpupdate

Windows command for making immediate group policy changes in an individual system.

ipconfig

Windows command that shows the TCP/IP configuration settings on a PC

taskkill

Windows command-line tool for killing running processes.

tasklist

Windows command-line tool for listing and managing processes.

Users Folder

Windows default location for content specific to each user account on a computer. It is divided into several folders such as Documents, Pictures, Music, and Videos.

ReadyBoost

Windows feature enabling the use of flash media as dedicated virtual memory.

UAC (User Account Control)

Windows feature implemented to stop unauthorized changes to Windows. UAC enables standard accounts to do common tasks and provides a permissions dialog box when standard and administrator, accounts do certain things that could potentially harm the computer (such as attempt to install a program).

Documents folder

Windows folder for storing user-created files.

Error Checking

Windows graphical tool that scans and fixes hard drive problems. Often referred to by the name of the executable, chkdsk, or Check Disk. The Mac OS X equivalent is the Disk Utility, and Linux offers a command-line tool called fsck.

Data Collector Sets

Windows log repository that accepts log entries from other Windows computers.

pinned apps

Windows method of attaching programs to the taskbar. A pinned app gets a permanent icon displayed on the taskbar.

Server Message Block (SMB)

Windows network file and print sharing protocol, though every major OS now supports it. Protocol of choice for LAN file servers. Uses TCP port 445 and UDP ports 137, 138 and 139.

ODBC Data Source Administrator

Windows programming tool for configuring the Open Database Connectivity (ODBC) coding standard. Data Source Administrator enables you to create and manage entries called Data Source Names (DSNs) that point ODBC to a database. DSNs are used by ODBC-aware applications to query ODBC to find their databases.

file association

Windows term for the proper program to open a particular file; for example, the file association for opening or .mp3 files might be Winamp.

Performance Monitor

Windows tool for observing a computer's performance.

Windows Memory Diagnostic

Windows tool that can be automatically scan a computer's RAM when a problem is encountered.

Remote Desktop Connection

Windows tool used to form a remote desktop connection and graphically access the GUI of a remote system.

Local Security Policy

Windows tool used to set local security policies on an individual system.

Resource Monitor

Windows utility that displays detailed performance information about a computer's CPU, memory, disk, and network activity.

HDBaseT

Wired video transmission system to carry uncompressed HD video over Cat 5a or Cat6 network cables.

IEEE 802.11

Wireless Ethernet standard more commonly known as Wi-Fi.

GSM (Global System for Mobile Communications)

Wireless data standard for mobile devices

infrastructure mode

Wireless networking mode that uses one or more WAPs to connect the wireless network nodes to a wired network segment.

WEP (Wired Equivalent Privacy)

Wireless security protocol that uses a standard 40-bit encryption to scramble data packets. Does not provide complete end-to-end encryption and is vulnerable to attack.

WPA (Wi-Fi Protected Access)

Wireless security protocol that uses encryption key integrity-checking/TKIP and EAP and is designed to improve on WEP's weaknesses. Supplanted by WPA 2.

WPA2 (Wi-Fi Protected Access 2)

Wireless security protocol, also known as IEEE 802.11i. uses the Advanced Encryption Standard (AES) and replaces WPA.

Bluetooth

Wireless technology designed to create small wireless networks preconfigured to do specific jobs, but not meant to replace full-function networks or Wi-Fi.

Radio Frequency Identification (RFID)

Wireless technology that uses small tags containing small amounts of digital information, and readers capable of accessing it. Passive RFID tags operate by harvesting some of the power a scanner or reader emits, enabling a vast array of applications. Common uses such as tracking inventory, identifying lost pets, contactless payments, authentication, and wireless door locks are just scratching the surface.

T568A

Wiring standard for Ethernet cable

T568B

Wiring standard for Ethernet cable

IMEI (International Mobile Equipment Identity)

a 15-digit number used to uniquely identify a mobile device, typically a smartphone or other device that connects to a cellular network.

Chromebook

a computer running the Google Chrome OS with the requirement of Internet access to operate. Instead of installing and running programs from the hard drive almost everything is run from the cloud.

ESD mat

a mat that dissipates ESD and is commonly used by technicians who repair and assemble computers at their workbenches or in an assembly line.

file

a named collection of stored data, instructions, or information

Botnet

a network of private computers infected with malicious software and controlled as a group without the owners' knowledge, e.g., to send spam messages.

icon

a small image or picture on a computer screen that is a symbol for folders, disks, peripherals, programs, etc.

heat dope

also known as thermal compound

Linux

an open-source version of the UNIX operating system

Personally Identifiable Information (PII)

any data that can be used to identify, locate, or contact an individual

closed source

any proprietary software licensed under exclusive legal right of the copyright holder

cd

command-line utility for changing the focus of the command prompt from one directory to another. Shorthand for "change directory".

PCIe 6/8-pin power connector

connector on some power supplies for powering a dedicated graphics card.

launchd

developed by Mac for automation; script tool to run all sorts of tasks automatically in the background

WAV

file format for audio that is the standard file type for storing audio on PCs

Search box

location on the Windows 10 Taskbar where users can input text and see suggestions (for settings, programs, file and popular web searches) that may be related.

traceroute

macOS and Linux command-line utility for following the path a packet takes between hosts. The Windows version is named tracert.

Spaces

macOS feature enabling multiple desktops.

Utilities

macOS folder that contains tools for performing services on a Mac beyond what's included in System Preferences, including Activity Monitor and Terminal.

Time Machine

macOS full backup tool that enables you to recover some or all files in the event of a crash; it also enables you to restore deleted files and recover previous versions of files.

Keychain

macOS password management and storage service that saves passwords for computer and non-computer environments. Also, the iCloud Keychain adds synchronization among any macOS and iOS devices connected to the Internet for a user account.

System Preferences

macOS tool containing many administrative functions

change

modify configuration or status of a system, such as updating an NTFS permission or modifying a password.

printer

output device that produces text and graphics on a physical medium such as paper

script

set of text instructions that tells a computer a series of commands to execute in a repeatable fashion.

MP3

short for MPEG-1 Layer 3, an advanced type of audio compression that reduces file size, enabling audio to be easily distributed over the Internet and to be digitally transmitted in real time

IRQ (Interrupt Request)

signal from a hardware device, such as a modem or a mouse, indicating that it needs the CPU's attention. In PCs, IRQs are sent along specific IRQ channels associated with a particular device. IRQ conflicts were a common problem in the past when adding expansion boards, but the plug-and-play specification has removed this headache in most cases.

audio jack

used to send or receive audio signals. used a 3.5 mm TRS connectors to connect audio devices

Ethernet over Power

uses the existing power lines within a building or home to provide data communications

Disk Cleanup

utility program to remove unnecessary files that may slow down the computer from hard drive

Authentication

verifying the identity of the person or device attempting to access the system