chapter 8 Computer Concepts
flash drive
A small, portable device that can carry 2 to 8 gigabytes or more of information and that plugs into a USB port; also called a thumb drive, jump drive, or portable drive.
zip drive
A small, portable disk drive primarily used for backing up information and archiving computer files (also called an external hard drive). A 100-megabyte Zip disk holds the equivalent of approximately 70 floppy disks; Often used to back up files that are on a desktop or laptop computer.
cursor
A symbol on the monitor screen that shows the location of the next character to be typed.
byte
A unit of data that contains 8 binary digits, or bits.
virtual reality
An artifical environment presented to a computer user that feels as if it were a real environment, often involving use of special gloves, earphones, and goggles to enhance the experience.
digital video disk (DVD)
An optical disk that holds apporximately 28 times more information than a CD; a DVD is most commonly used to hold full-length movies. Compared with a CD, which holds approximately 600 megabytes, a DVD can hold approximately 4.7 gigabytes. Also called a digital versatile disk.
backup
Any type of storage that prevents the loss of files with hard disk failure.
gigabyte (GB)
Approximately 1 billion bytes
megabyte (MB)
Approximately 1 million bytes.
terabyte (TB)
Approximately 1 trillion bytes.
Kilobyte (KB)
Approximately 1,024 bytes.
application software
Computer programs designed to perform specfic tasks.
disk drives
Devices that load a program or data stored on a disk into the computer.
switch
In networks, a device that filters infromation between LAN segments and reduces overall network traffic and increases speed and bandwidth use efficiency.
input
Information entered into and used by the computer.
output
Information processed by the computer and transmitted to a monitor, printer, or other device.
cookies
Messages sent to a Web browser from a Web server that identify users and can prepare custom Web pages for them, possibly displaying their name on return to the site.
icons
Pictures, often on the monitor screen "desktop," that represent programs or objects. Clicking on an icon directs the user to the program.
search engines
Programs that search documents for keywords and return a list of documents containing those words.
queries
Requests for information from a data base.
e-commerce
Short for electronic commerce; used to describe the sale and purchase of goods and services over the internet; doing business over the internet.
Short for electronic mail; commucations transmitted via computer or computer network.
modem
Short for modulator-demoduulator; a device that allows information to be transmitted over telephone lines at speeds measured in bits per second (bps). The modem speed generally is listed somewhere on the unit.
browsers
Software programs that allow users to view Web pages on the internet (e.g., internet Explorer, Firefox).
cache
Special, high-speed storage that either can be part of the computer's main memory or a separate storage device. One function of a cache is to store Web sites visitied in the computer memory for faster recall the next time the Web site is requested.
tcp/ip
The acronym for transmission control protocol/internet protocol; a suite of communications protocols used to connect users or hosts to the internet.
url
The acronym for uniform resource locator; specifies the global address of documents or information on the internet. The URL provides the IP address and the domain name for the Web page, such as microsoft.com
html
The acronymn for hypertext markup language, the language used to create documents for the internet.
http
The acronymn for hypertext transfer protocol, which defines how messages are formatted and transmitted over the Internet. When a URL is entered into the computer, an HTTP command tells the Web server to retrive the requested Web page.
artificial intelligence
The aspect of computer science that deals with computers taking on the attiributes of humans, such as mimicking human thought.
domain name
The intial part of a URL listing; the domain and name of the host or server, indicating the publisher of a Web page site.
megahertz (MHz)
The measuring device for microprocessors. A megahertz is 1 million cycles of electromagnetic currency alternation per second and is used as a unit of measure for the clock speed of computer microprocessors.
cyberspace
The nonphysical space of the online world of computer networks in which communication takes place.
system software
The operating system and all utility programs that allow the computer to funcation and perform operations.
hardware
The physical components of the computer system, such as the central processing unit (CPU), monitor, and printer.
multimedia
The presentation of graphics, animation, video, sound, and text on a computer in an integrated way or all at once. CD-ROMs are efficient multimedia devices.
device driver
The program or commands given to a device connected to a computer that enable the device to function. For instance, a printer may come equipped with software that must be loaded onto the computer first so that the printer will work.
hard copy
The readable paper copy or printout of information.
telecommunications
The science and technology of communication by transmission of information from one location to another via telephone, television, telegraph, or statelite.
bits
The smallest units of information inside the computer, each represented either by the digit "0" or "1"; 8 bits equal 1 byte.
environment
The state of a computer, usually determined by the programs running and hardware and software characterisctics.
format
To magnetically create tracks on a disk where information will be stored, usually done by the manufacturer of the disk.
database
A collection of related files that serves as a foundation for retrieving information.
bookmark
A command in a browser that marks the IP address of a Web site so that it can be saved and recalled quickly without typing the entire Web address.
hub
A common connection point for devices in a network with multiple ports, often used to connect segments of a local area network (LAN).
server
A computer or device on a network that manages shared network resoures.
cd burner
A deivce that can "write" data on a blank compact disk (CD) or copy data from one CD to a blank CD.
scanner
A device that reads text or illustrations on a printed page and can translate the information on that page into a form the computer can understand.
router (rau-ter)
A device used to connect any number of LANs, which communicate with other routers and determine the best route between any two hosts.
personal digital assistant (PDA)
A handheld computer capable of functions such as mobile telephony, Web browsing, and media playing. PDAs typically include an appointment calendar, to-do list, address book, note programs, and e-mail and/or Web capabilites
digital subscriber line (DSL)
A high-speed, sophisticated modulation scheme that operates over existing copper telephone wiring systems; often referred to as "last-mile technologies," because DSL is used for connections from a telephone switching station to a home office and not between switching stations.
computer
A machine designed to accept, store, process, and produce information.
