DSST Chapter 4: Computing and Information Technology
Megabyte MB
1 million bytes
Terabyte
1 trillion bytes or 1000 GB
kilobyte KB
1024 bytes and refers to small computer files
software life cycle
6 stages: 1. preliminary investigation, 2. system analysis, 3. system design, 4. system development, 5. system implementation, 6. system maintenance
hyperlink
An address that refers to another location, such as a website, a different slide, or an external file.
Keyboard
An input device that allows the user to type information into the computer or software program within the computer
Monitor
An output device that displays what the user is doing on the computer
Storage
Area where data is left permanently in files when not needed for processing; a hard disk drive inside a PC serves as the main storage device; also known as a secondary storage
ALU
Arithmetic logical unit that contains the electronic circuitry that executes all arithmetic and logical operations or mathematical calculations. The ALU may need to perform a mathematical calculation in order to decode the instruction so that the CPU can execute the instruction
Processing Components
CPU, ALU, RAM, Software
CPU
Central Processing Unit that manipulates data. The CPU fetches the instruction from its memory and executes it after decoding the instruction
File
Collection of data given a specific name, maybe stored on a hard disk, CD, DVD, or flash drive
Peripheral device
Components or equipment that expand or enhance the input, output, and storage functions of a computer; includes printers, disk drives, scanners, joysticks, speakers, and digital cameras
RAM chips
DRAM, SDRAM, SRAM, DDR-SDRAM
DRAM
Dynamic RAM; dynamic means that it needs to be refreshed constantly by the CPU or its contents are lost
file transfer protocol
FTP is a standard network protocol that uses separate control and data connections between the server and the client, and it is built on a client-server model architecture.
Basic Computer terms
File, Hardware, Input, Microprocessor chip, motherboard, Network, Output, Peripheral device, Storage
Input
Information placed into a computer through a device like a keyboard, thermostat, mouse, camera, or microphone
IDS
Intrusion detection system. A detective control used to detect attacks after they occur. A signature-based IDS (also called definition-based) uses a database of predefined traffic patterns. An anomaly-based IDS (also called behavior-based) starts with a performance baseline of normal behavior and compares network traffic against this baseline. An IDS can be either host-based (HIDS) or network-based (NIDS). In contrast, a firewall is a preventative control that attempts to prevent the attacks before they occur. An IPS is a preventative control that will stop an attack in progress.
Types of networks
LAN, MAN, NAN, PAN, WAN, HAN
MAN
Metropolitan area network, serves a 50 mile area; local internet service providers and cable tv companies are often MANs
network interface card
NIC circuitry that transmits and receives data on a LAN; often inserted into an expansion slot
Software
Programs that instruct computers how to perform specific tasks
Cache Memory
RAM that the computer microprocessor can access quickly when needed. Stores program instructions that software programs frequently access. This storage allows the software programs to access these instructions faster, which allows the software to run quickly and efficiently and to use fewer resources.
RAM
Random-access memory; temporary or working storage that holds data, software instructions, and the operating system for quick access, also known as primary storage or memory
ROM
Read only memory, contain a computer's fixed startup instructions loaded at the factory. The instructions cannot be erased, and are not volatile like RAM chips.
Output
Results generated by a computer, such as reports, graphs, and pictures that are provided by an output device like a screen or a printer
Microprocessor chip
Small piece of silicon that holds millions of tiny electronic circuits; serve as CPU of most computers; can be programmed to perform certain tasks
search hijacker
Spyware that intercepts actual search requests and re-routes the user to other sites
SRAM
Static RAM; faster than DRAM and holds onto its contents without needing to be refreshed by the CPU
Disk storage
Storage that provides a means to record data by various electronic, magnetic, optical, or mechanical changes to a surface layer of one or more rotating disks.
SDRAM
Synchronous dynamic RAM; synchronized by the system clock and faster than DRAM
machine language
The basic language of any computer as represented by binary digits, the first generation of computer languages.
booting
The sequence of events that occurs when you turn the computer on and when it becomes ready to process data.
ARPANET
The starting point for today's Internet, created in 1969 by the US Department of Defense.
microcontroller
Tiny, specialized microprocessor built into the device it controls: also known as an embedded computer. Used in automobiles, MP3 players, digital cameras, and electronic appliances
cloud computing
a means for storing and accessing files, data, and programs via the internet
Micro SD card
a small card that functions as an input and output device; it allows files to be stored and also extracts files to the computer
insert/delete
adding or inserting text can be done with the Insert key or by moving the cursor to a specific location. deleting or removing text can be accomplished with the delete or backspace key.
Secondary storage
additional storage that is separate from the main memory
shrink-wrap license
agreement printed on package that becomes effective when package is opened
peer2peer
all workstations on the network communicate with each other without depending on a server.
Instant messaging (IM)
allows for real-time communication through transmitted text messages
telnet
allows remote access to another person's computer
presentation software
allows users to create dynamic, engaging presentations without having to depend solely on note cards
visual programming
allows users to develop programs by drawing, pointing, or clicking on icons that represent certain programming routines
conferencing software
allows users to instant message each other, view attendees web cams, speak to attendees, listen to each other, share files, view videos and presentation, and write messages on a whiteboard
enterprise software
also known as enterprise application software or EAS; is used to satisfy an organization's needs, e.g., government, businesses, educational institutions, clubs, and charities
editors
also referred to as text editors, are computer programs that allow users to enter, change, store, and print text. a text editor often displays and empty screen or scrollable page with visible line numbers (at a fixed length) a user is able to fill in the lines with text, scroll forward, scroll backward, save the document, go to a new page, and make global changes. the document can be printed and displayed once it is saved. program language source statements, technical manuals, and other documents can be created using text editors.
USB flash drive
an input and output device that allows files to be stored and extracts files to the computer
Mouse
an input device that allows the user to click icons or place the cursor in a location so that the user an perform a function on the keyboard to input information in the computer
Printer
an output device that allows files to be printed from the computer as hard copies
Speaker
an output device that allows the user to hear audio from the computer
readability formula
analyzes the reading level of a document based on sentence length and vocabulary
spam
annoyances
application software
any computer program that enables a user to perform a certain task, such as word processing or desktop publishing.
node
any device attached to a network, such as a PC, storage device, or scanner
Natural languages
associated with artificial intelligence (technology geared toward humanizing machines)
pretexting
attacker creates a convincing scenario or situation that will allow him or her to steal the victim's personal information.
quid pro quo
attacker promises something, usually some type of good or product in exchange for information.
freeware
available for free
shareware
available for free on a trial basis; must pay to continue using it at the end of the trial period
public domain software
available to the public without any restrictions
directory name
bibe name on the server for the directory from which the browser needs to retrieve a file
Bps
bits per second or bits/sec
hackers
break into computers for fun, such as thrill seeker hackers, or for work purposes, such as white-hat hackers
crackers
break into systems for malicious purposes
function
built-in formula provided by software
cell address
cell's position as designed by the column letter and row number
database
collection of data stored on any type of computer
World wide web
collection of multimedia files linked and accessed through the internet
multimedia
combination of multiple forms of media, including text, graphics, audio, video, animation and interactive content.
demoware
commercial software available in a trial version that has limited features; often pre-installed on new computers
types of proprietary software
commercial, shareware, freeware, demoware, open source
proprietary software
commercially sold or free, has restrictions on its use
Hub
common connection point for devices in a network where data arrives and is forwarded out; hubs are half-duplex devices that transmit data in both directions but only one direction at a time
Network
communication system
CMOS
complementary metal-oxide semiconductor) chips are battery powered, so they do not lose their contents when power is interrupted. Hold flexible startup instructions kept up to date when the computer is not on, such as time and date.
record
complete set of fields
microcomputer
computing device with a microprocessor intended to meet needs of individuals; also known as a personal computer or PC; capable of handling e-mail, word processing, photo editing, and other applications; available as laptops, desktops, or handheld computers; may be connected to a computer network
1. Preliminary Investigation
conduct an initial analysis, propose alternative solutions, indicate costs/benefits, submit preliminary plan in a written report to executives
operating system
controls activities occurring within the computer system and affects how a person is able to use a computer
5. system implementation
convert hardware, software, and files of old system to new system with direct, parallel, phased, or pilot implementation; direct implementation means user stops using old system and starts using new one; parallel implementation means both old and new systems are used at the same time until the new one seems reliable; phased implementation means parts of the new system are phased in gradually; pilot implementation means a few users test the entire system before everyone else uses it; users are then trained on the new system.
cybercrime
cracker can hack personal computers as well as company networks and servers to steal passwords, personal identification numbers, and other personal information.
3. system design
create a preliminary design or a prototype of the software system, and then create a detailed design that defines input/output requirements, storage/processing requirements, and system controls and backup; write a report summarizing the preliminary and detail designs.
Object-oriented programming (OOP)
data and processing instructions are combined into objects, modules of programming code that can be used in other programs
bandwidth
data transmission capacity of a communications channel
4. system development
develop the software; software is tested in two stages: unit testing of individual parts and then system testing with actual data; system testing may involve using incorrect data or large quantities of data to force the system into failing or crashing. Programmers also need to debug in order to identify and remove errors
virus
deviant program that copies itself and infects computers; attaches to hard disks and destroys and corrupts data
communications hardware
devices that can transmit either analog or digital signals over cable, wireless technology, or telephone
switch
devices that connects computers to a network; switches are full-duplex devices that transmit data back and forth at the same time
Scanners
devices that scan and copy documents and convert them to an electronic format or digital data
End User License Agreement (EULA)
displayed on screen during first installation
DDR-SDRAM
double-data rate synchronous dynamic RAM; the newest and most popular RAM chip
backup utilities
duplicate copies of a system's hard disk in case of hard drive failure.
Newsgroups
electronic bulletin boards where users participate in written discussions about various subjects
data compression utilities
eliminate unneeded data and gaps in a computer's storage space so that less
social networking sites
enable users to post pictures and messages about personal activities and interests for the viewing pleasure of others
spreadsheet software
enables sers to enter numerical data and formulas into rows and columns
word processing software
enables users to create, edit, format, print and store documens such as reports, letters, memos, and manuscripts.
query by example
examples of the data being sought
workstation
expensive and powerful personal (PC) designed for specific, complex tasks like medical imaging or computer-aided design (CAD); term also used to refer to a PC connected to a network
Peripheral devices
external auxiliary devices that connect to your computer
hierarchical database
fields ad records are arranged in related groups similar to a family tree with lower-level (child) records subordinate to higher-level (parent) records.
defragmenter utilities
find and reorganize the scattered files on a hard drive to speed up operation
programming
five step process to create instructions for a computer: 1. clarify programming needs regarding input, output, and processing requirements. 2. Design a solution with modeling tools. 3. Write, or code, the program with the appropriate programming language. 4. test the program to remove errors or bugs. 5. write program documentation about what the program does and how to use it and maintain the program with modifications, repairs, and tests.
identity theft
forging checks, creating fake IDs, or producing replica credit and debit cards.
spoofing
forging the name of an e-mail sender
Algorithm
formula for solving a specific problem
spyware
gather a user's personal information for advertising purposes
2. system analysis
gather data from surveys and observations, analyze data using modeling tools to create graphic representations of the software system, and write a report for management.
Perl (practical extraction and report language)
general-purpose language used for web development, network programming, system administration, and GUI development
grammar checker
grammar mistakes are highlighted but not automatically corrected.
GUI
graphical user interface, allows users to choose icons or commands from menus with a mouse or a keyboard.
byte
group of eight binary digits
network
group of interconnected computers, phones, and other communications devices that are able to communicate with each other and share resources
range
groups of cells next to each other
supercomputer
high-capacity machine with thousands of microprocessors; fastest and most expensive type; able to process trillions of calculations every second; used for weather forecasting, physical simulations, and image processing
HAN
home area network, connects the digital devices inside a home
web protocol
http:// and https:// Hypertext transfer protocol (HTTP) refers to the communications rules enabling browsers to connect to web servers. HTTPS is the secure version of Hypertext Transfer Protocol
open source
includes source codes, so programmers can make modifications and improvements
file name and extension
index.htm file name is the specific page-index.htm; .htm is an extension of the file name that tells the browser that it is an HTML (hypertext markup language) file; HTML is a standardized format that specifies the layout for webpages
formula
instructions for calculations
wizards
interactive utilities programs that lead users through steps to format a certain type of document, such as a memo or a resume
gateway
interface allowing communication between different types of networks, such as between a LAN and a WAN
bridge
interface that connects the same types of networks like two LANs joined to create a larger network
Netiquette
internet etiquette, refers to various guidelines to ensure civil and effective communication when participating in online discussion groups or exchanging e-mails
IPS
intrusion prevention systems, control tool, best compared to a firewall, rules can be set up and initiated to decide what is allowable and what is not allowable. examines network traffic flows and attempts to detect and prevent vulnerability threats
Level 1 cache or L1
is a small cache that is embedded in the processor chip; although it is small, it is really fast.
cyberbullying
kids threaten and harass other kids through electronic communication
cells
land areas served by one or more cell towers, which transmit voice, data etc
mainframe computer
large, fast, and expensive computer typically used by large organizations, such as banks, airlanes, universities, and government agencies; used to process, store, and manage large quantities of data; accessed from a computer terminal
Level 2 cache or L2
larger than an L1 cache and it is usually located on a CPU or a separate chip. A high-speed alternative system bus connects the cache to the CPU to prevent it from slowing down when there is a lot of traffic (activity) on the main system bus.
telecommunications law
laws and policies that are in place to regulate electronic communications and broadcasting within the united states, regulated by the federal government (FCC) internet was included in 1996.
Single-user license
limits use of the software to one person at a time
systems software
link between the user, application software, and the computer hardware
LAN
local area network, serves a very limited geographical area, such as one building
find/replace
locate a word, phrase, or number with the Find or Search function. The replace command enables users to replace a word, phrase, or number automatically with something else.
cell
location where a row and a column intersect
backbone
main highway that connects an organization's computer networks
Host
mainframe or midsize central computer that controls a client/server network
malware
malicious software, any program designed to secretly infiltrate a computer and disrupt normal operations
social engineering attack
many different forms, ranging from attacking computers to attempting to gain people's personal information in an effort to commit fraudulent acts.
site license
may be used on all computers at a specific location and is purchased for a flat fee
Biometrics
metrics that use human characteristics as a form of identification.
communications satellites
microwave relay stations orbiting the earth, serve as a basis for Global Positioning System (GPS)
6. system maintenance
modify and improve the system with audits and evaluations
Cut/Copy and paste
move text with copy or cut to the clipboard, a holding area in memory, and then use Paste to relocate the text somewhere else
NAN
neighborhood area network, connects a limited geographical area, often several buildings
ethernet
nodes are connected by wire or cable
values
numbers or dates entered into a cell
java
object-oriented language used for writing compact programs to be downloaded over the internet and immediately executed; similar to C++ but simpler to use
JavaScript
object-oriented scripting language supported in web browsers that adds interactive functions to HTML pages
COBOL (CommonBusiness-Oriented Language)
oldest programming language; still used in business, finance, and administrative systems
thesaurus
on-screen thesaurus lists synonyms
nanosecond
one billionth of a second
microsecond
one millionth of a second
C++
one of the most popular and commonly used languages; combines traditional C programming with object-oriented functions; used in writing systems software, application software, device drivers, and video game software
relational databases
organize data into related tables with rows and columns
PAN
personal area network Uses short range (30 feet) wireless technology for connecting personal digital devices
antivirus software
popular method of dealing with viruses, pop-up ads, and spam
Templates
preformatted style guides for structuring a document
multiple-user license
price based on the number of users; specified number of users may use the software at any given time
concurrent-use license
priced per copy; specific number of copies may be used at the same time
encryption
process of scrambling or hiding data into an unreadable form to prevent unauthorized access
data mining/analytics
process where patterns or large data sets are discovered.
client/server network
processing is divided between the clients, which are the workstations, and the server that manages shared devices such as printers and scanners.
trojan horse
program that appears to be useful but actually carries a virus or destructive instructions; typically offered for free in the form of a game or a screen saver; may invite backdoor programs that enable illegitimate users to gain control of a computer secretly
worm
program that repeatedly copies itself into a computer's memory; excessive copies cause computers to crash
antivirus software
programs that scan a computer's hard disk and memory to identify and destroy viruses
two software categories
public domain software & proprietary software
natural language query
query constructed in human instead of machine language
band
range of electromagnetic frequency
pharming
redirecting users to fake websites
debuggers
referred to as debugging tools, are software programs used to test and find bugs/errors in programs. in the event a program crashes, a debugger will show the location of the error within the program. some debuggers can modify programs while they are running and some can run programs step-by-step
Denial-of-service attack (DoS)
repeated fraudulent requests of a computer system or network that result in a system overload
data recovery utilities
restore damaged or corrupted data caused by viruses or hardware failures
subject directory
search for information by choosing lists of categories or topics, such as "sports" or "arts and humanities." yahoo! and Galaxy include subject directories
keyword index
search for information with one or more keywords, and the search engine displays a list of web pages containing the keywords
metaseaerch engine
search more than one search engine at the same time. Webcrawler and Dogpile are metasearch engines
phishing
sending forged e-mail with the intention of fooling users into revealing private information
broadcast radio
sends data over long distances between states and countries; requires transmitters and receivers
Structured Query Language (SQL)
set of command words to instruct the computer to locate, sort, or modify data
protocol
set of rules that govern the exchange of data between hardware and software components; each device in a network has a unique Internet protocol (IP) address so that data is routed properly
mobile devices
small (mini-computers) devices that provide most of the same functions as a regular personal computer or laptop; some mobile devices can provide a means of telephonic communication
applet
small application that can perform a specific function
phishing
social engineering attack. attackers attempt to obtain others' personal information by using hyperlinks, embedded links, and fraudulent websites.
software as a service (SaaS)
software is licensed based on a subscription (typically monthly or yearly) and is considered to be an on-demand software choice
compilers
software programs that take a developer's high-level written source code and convert it into a binary code (low-level object code) in machine language so that the processor can understand it. once the processor understands it, the processor then executes the object code.
list servers
software programs used to distribute messages to an online mailing list
commercial
sold in stores and on websites
router
special computer that joines multiple networks together and directs communicating messages, such as e-mails and HTML files
key logger
spyware that records characters being typed and relays the information to other internet users, making it possible for strangers to know passwords and other private information
browser hijacker
spyware that secretly changes browser settings
Flash memory
store flexible programs in computers, cell phones, digital cameras, and MP3 players. Nonvolatile, can be erased and reprogrammed.
firewall
system of hardware and/or software that shields a computer or network from intruders by analyzing, controlling, and filtering incoming and outgoing packets
network operating system
systems software that manages network activity, such as data flow and security
label
text used to describe data
multitasking
the ability of an operating system to run more than one software program at a time
Motherboard
the main circuit board of the computer
Hardware
the physical components, or parts, of the computer
Spelling checker
this tests for incorrectly spelled words, which are indicated by a wavy line in word
interpreters
translate high-level instructions into an intermediate form prior to execution. an interpreter does not go through the compilation stage where machine instructions are generated. it immediately executes high-level programs
microwave radio
transmits voice and data with super-high=frequency radio that can be aimed in one direction; more carrying capacity than broadcast radio waves; bluetooth, for example, involves short-range microwave transmissions
infrared transmission
transports data with infrared-light waves that are just below the visible light spectrum
computer-aided design (CAD)
type of 3D graphics software used by architects and engineers to create product specifications and design blueprints.
hypermedia databases
type of object oriented database with links to graphics, audio, and video
hypertext databases
type of object-oriented database with text links to other documents
pop-up generator
type of spyware that tracks web surfing and online purchases so marketers can send unsolicited pop-up ads targeted to the user's interests; also known as adware
assemblers
types of computer programs that interpret software programs written in assembly language. they interpret the assembly language into machine language and machine code so that the computer can execute the instructions. also known as assembly language compilers. they allow software and application developers to gain access to the computer's hardware architecture and components. they also allow software and application developers to manage and operate the computer's hardware architecture and components
Level 3 cache or L3
typically double the random-access memory speed and is considered a specialized memory designed to improve the L1 and L2's performance. When an instruction is referenced in the L3 cache, it is usually elevated to a higher tier cache
URL
uniform resource locator
password
unique set of symbols, words, or codes used for restricting access to a computer or network
packet
unit of data transmitted over a network; communications, such as e-mails, are divided into packets when sent and reassembled upon arrival
Gigahertz (GHz)
unit of measurement when discussing processor speed
spam
unsolicited e-mail, typically in the form of advertising or chain letters
biometrics
use of physical attributes like fingerprints, voices, faces, or eyes to confirm an individual's identity
profilers
use statistical, simulation, event-based, or instrumented methods to monitor or measure program source code or its binary executable form. profilers measure the time complexity and the space or memory of a program, how certain instructions are used, and/or the duration and frequency of particular function calls
Object-oriented database
used most often in manufacturing or scientific settings.
multidimensional databases
useful in analyzing large amounts of data that can be grouped in more than two dimensions.
graphics software
users create, manipulate, and print graphics such as drawings, photographs, and images that appear on a computer screen
filtering software
utility used by parents to prevent children from accessing inappropriate websites
WAN
wide area network Covers a large geographical area, such as a country or the world, and typically consists of several smaller networks; the internet is the world's largest WAN
internet
worldwide communication infrastructure that connects compputer networks
Domain name
www.nps.gov location on the internet; last three letters describe the domain type-gov (government), .com (commercial), .net (network), .mil (military), or .int (international organization)