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)