Computer Tech Hardware

mouse

A computer mouse is a handheld hardware input device that controls a cursor in a GUI and can move and select text, icons, files, and folders. For desktop computers, the mouse is placed on a flat surface such as a mouse pad or a desk and is placed in front of your computer.

digit

A digit is a single character in a numeric system. For example, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 are all digits.

optical disc

Alternatively referred to as a disc drive, optical media, optical storage, Optical disc drive (ODD), and optical disk, an optical disc is any media read using a laser assembly. The most common types of optical media are Blu-ray, CDs, and DVDs. Computers can read and write to CDs and DVDs using a CD Writer or DVD Writer drive, and a Blu-ray is read with a Blu-ray drive. Drives such as a CD-R and DVD-R drive that can read and write information to discs are known as magneto-optic (MO).

peripheral

An external device, such as a keyboard or monitor, connected via cables to the system central processing unit. Alternatively referred to as an auxiliary device, a peripheral is hardware input device or output device that gives a computer additional functionality. Peripheral devices, however, are not essential for the computer to perform it's basic tasks; they can' be though of as an enhancement to the user's experience.

input device

An input device is any hardware device that sends data to a computer, allowing you to interact with and control the computer.

motherboard

The motherboard is a printed circuit board that is the foundation of a computer, located on the back side or at the bottom of the computer chassis. It allocates power and allows communication to the CPU, RAM, and all other computer hardware components.

volatile memory

Volatile memory is a type of storage whose contents are erased when the system's power is turned off or interrupted. For example, RAM is volatile. When you are working on a document, it is kept in RAM, and if the computer loses power, your work will be lost. For this reason, you should save your document to a file on a non-volatile storage medium, such as your hard drive.

TB (terabyte)

Approximately 1 million megabytes.

keyboard

Input device, similar to a typewriter keyboard, for entering data and commands into the computer.

CD-RW

Short for Read/Write, R/W is a drive and CD media that was first introduced in 1997 that is capable of being written to and read. Unlike a traditional CD-R disc that can only be written to once, these discs allow data to be erased and re-written multiple times.

sound card

A circuit board that allows the PC to accept microphone input, play music and other sound through speakers or headphones, and process sound in a variety of ways.

digital

An electronic signal that is sent as binary digits of either ON (the number one) or OFF (the number zero). In the illustration, a digital signal is the segments that are up or down for either ON or OFF and discontinuous; unlike an analog signal, which is continuous and more like a wave.

scanner

An input device that makes a digital representation of any printed image. See flatbed scanners, slide scanners, drum scanners, and sheet-fed scanners. When referring to hardware, a scanner or optical scanner is a hardware input device that optically "reads" and image and converts it into a digital signal. For example, a scanner may be used to convert a printed picture, drawing, or document (hard copy) into a digital file which can be edited on a computer.

information

Anything that can be communicated. (Some more restrictive definitions of information say that it is data that is organized or processed.)

MB (meg or megabyte)

Approximately 1,000 KB, or 1 million bytes. An MB is a measurement used with computer storage media that can equal to 1,048,576 (220) bytes.

GB (gig or gigabyte)

Approximately 1,000 MB.

external drive

More commonly referred to as an external drive, external storage is storage that is not part of the computer. Examples of external storage are floppy disk drives, hard drives, tape drives, etc.

output device

A device for sending information from the computer, such as a monitor or printer. An output device is any peripheral that receives data from a computer, usually for display, projection, or physical reproduction. For example, the image shows an inkjet printer, an output device that can make a hard copy of any information shown on your monitor, which is another example of an output device. Monitors and printers are two of the most common output devices used with a computer.

file

A file is an object on a computer that stores data, information, settings, or commands used with a computer program. In a graphical user interface (GUI) such as Microsoft Windows, files display as icons that relate to the program that opens the file. For example, the picture is an icon associated with Adobe Acrobat PDF files. If this file was on your computer, double-clicking the icon in Windows would open that file in Adobe Acrobat or the PDF reader installed on the computer.

hard disk

A hard disk drive (sometimes abbreviated as Hard drive, HD, or HDD) is a non-volatile memory hardware device that permanently stores and retrieves data on a computer. A hard drive consists of one or more platters to which data is written using a magnetic head, all inside of an air-sealed casing.

laser printer

A nonimpact printer that uses a laser beam to create patterns of electrical charges on a rotating drum. The charged patterns attract black toner and transfer it to paper as the drum rotates.

random access

A storage method that allows information retrieval without regard to the order in which it was recorded. Sometimes referred to as machine access or random access, direct access is a term used to describe a computer's ability to immediately locate and retrieve data from a storage device. This method is often contrasted with sequential access, in which the device must start at the beginning and read through all of the information in order until the requested data is found. A hard drive is a good example of a device capable of directly accessing data.

sequential access

A storage method that requires the user to retrieve information by zipping through it in the order in which it was recorded. Alternatively referred to as serial access, sequential access is a method of retrieving data from a storage device. With sequential access, the device must move through all information up to the location where it is attempting to read or write. This method is often contrasted with random access, in which the device may move directly to a specified location in memory.

KB (K or kilobyte)

Abbreviated as K, kB, and KB, a kilobyte is equal to 1,024 bytes.

expansion card

Alternatively referred to as an add-on card, expansion board, internal card, interface adapter, or card, an expansion card is a PCB that fits into an expansion slot on a desktop computer. An expansion card is used to give a computer additional capabilities, such as enhanced video performance via a graphics card.

ASCII

American Standard Code for Information Interchange, which represents characters as 8-bit codes. Allows the binary computer to work with letters, digits, and special characters. Short for American Standard Code for Information Interexchange, ASCII is an standard that assigns letters, numbers, and other characters within the 256 slots available in the 8-bit code. The ASCII decimal (Dec) number is created from binary, which is the language of all computers.

liquid crystal display (LCD)

Flat-panel displays, once primarily used for portable computers but now replacing bulkier CRT monitors for desktops. Short for Liquid-Crystal Display, LCD is a flat display technology used in laptops, cell phones, calculators, digital cameras, and flat screen displays. The LCD is made of two sheets of a flexible polarizing material and a layer of liquid crystal solution between the two. An LCD is available as an active matrix, dual-scan, or passive-matrix display and are most common with laptop computers.

data

In general, data is any set of characters that has been gathered and translated for some purpose, usually analysis. It can be any character, including text and numbers, pictures, sound, or video. If data is not put into context, it doesn't do anything to a human or computer.

ROM (Read Only Memory)

Memory that includes permanent information only. The computer can only read information from it; it can never write any new information on it. Short for Read-Only Memory, ROM is a storage medium that is used with computers and other electronic devices. As the name indicates, data stored in ROM may only be read. It is either modified with extreme difficulty or not at all. ROM is mostly used for firmware updates. A simple example of ROM is the cartridge used with video game consoles, which allows one system to run multiple games.

non-volatile memory

NV or non-volatile memory is a term used to describe memory or storage that is saved regardless if the computer has power. It's also called persistent storage or permanent storage. An example of non-volatile memory and storage is a computer hard drive, flash memory, and ROM. Data stored on a hard drive remains there regardless if the drive has power, making it the best place to store your files. Non-volatile memory also stores your computer's time and system settings even when the power is off.

central processing unit (CPU)

Part of the computer that processes information, performs arithmetic calculations, and makes basic decisions based on information values. Stands for "Central Processing Unit." The CPU is the primary component of a computer that processes instructions. It runs the operating system and applications, constantly receiving input from the user or active software programs. It processes the data and produces output, which may stored by an application or displayed on the screen.

RAM (Random Access Memory)

RAM (random access memory) Memory that stores program instructions and data temporarily. Alternatively referred to as main memory, primary memory, or system memory, Random Access Memory (RAM) is a hardware device that allows information to be stored and retrieved on a computer. RAM is usually associated with DRAM, which is a type of memory module. Because information is accessed randomly instead of sequentially like it is on a CD or hard drive, the computer can access the data much faster. However, unlike ROM or the hard drive, RAM is a volatile memory and requires power to keep the data accessible. If the computer is turned off, all data contained in RAM is lost.

DVD

Short for Digital Versatile Disc or Digital Video Disc, a DVD or DVD-ROM is a disc capable of storing large amounts of data on one disc the size of a standard Compact Disc.

GPU (graphics processing unit)

Short for Graphics Processing Unit, GPU is an electronic circuit used to speed up the creation of both 2D and 3D images. GPUs can either be integrated, meaning they are built into the computer's CPU or motherboard, or they can be dedicated, meaning they are a separate piece of hardware known as a video card. By having a separate processor, the GPU allows the computer's CPU resources to be used for other important tasks. In the picture is an example of a GPU on a video card without the heat sink.

solid-state storage

Short for Solid-State Drive or Solid-State Disk, SSD is a drive that uses non-volatile memory as a means of storing and accessing data, much like computer RAM. Unlike a hard drive, an SSD has no moving parts, which gives it advantages such as accessing stored information faster, noiseless operation, higher reliability, and lower power consumption. The picture shows an example of an SSD made by Crucial.

USB (universal serial bus)

Short for Universal Serial Bus, USB (pronounced yoo-es-bee) is a plug-and-play interface that allows a computer to communicate with peripheral and other devices. USB-connected devices cover a broad range; anything from keyboards and mice, to music players and flash drives.

port

Socket that allows information to pass in and out. When referring to a physical device, a hardware port or peripheral port is a hole or connection found on the front or back of a computer. Ports allow computers to access external devices such as printers. Below is a short listing of the different computer ports you may find on a computer. The picture shows an example of a type of port on the back of a computer.

bit

Sometimes abbreviated as b, a bit is short for binary digit and is a single unit of information that can have a value of either 0 or 1 (off or on, false or true, low or high). Eight bits make a byte, as shown in the picture. So, if you had two bytes (word) it would be 16 bits (2 x 8=16) and 10 bytes would be 80 bits (10 x 8=80).

memory

Stores programs and the data they need to be instantly accessible to the CPU. Computer memory is any physical device capable of storing information temporarily or permanently. For example, Random Access Memory (RAM), is a volatile memory that stores information on an integrated circuit used by the operating system, software, and hardware.

flash memory

This type of memory is an integrated circuit that does not need continuous power to retain the data, but is a bit more expensive than magnetic storage. Today, flash memory is becoming more popular, and solid-state drives are a practical replacement for large hard drives if you have the extra money. Flash memory is widely used with car radios, cell phones, digital cameras, PDAs, solid-state drives, and printers. The picture is an example of a MicroSD flash memory card.

byte

byte is a term first coined by Werner Buchholz in 1956 and later became more of a standard thanks to Bob Bemer and others. A byte is data equal to either seven or eight bits depending if it needs error correction (parity). You can think of a byte as one letter, for example, the letter 'h' is one byte or eight bits and the word 'hope' as four bytes or 32 bits (4*8). When looking at the size of a file, a byte is the smallest measurement size listed in operating systems.