Glossary
Other Technical Dictionaries/Glossaries
Acronym Glossary CNET Internet Glossary ILC Glossary of Internet Terms OneLook Dictionaries
Data Representations of facts. Raw material for information. (Plural of datum.)
Data bits A data communications parameter that refers to a timing unit.
Data bus A common pathway between RAM, cache memory, and the processor through which data and instructions are transferred. (See also address bus.)
Data cartridge Magnetic tape storage in cassette format.
Data communications The collection and distribution of the electronic representation of information between two locations.
Data communications specialist A person who designs and implements computer networks.
Data compression A method of reducing secondary storage requirements for computer files.
Data entry The transcription of source data into a machine-readable format.
Data entry operator A person who uses key entry devices to transcribe data into machine-readable format.
Data file This file contains data organized into records.
Data flow diagram A design technique that permits documentation of a system or program at several levels of generality.
Data item The value of a field. (Compare with field.)
Data mining An analytical technique that involves the analysis of large databases, such as data warehouses, to identify possible trends and problems.
Data path The electronic channel through which data flows within a computer system.
Data processing (DP) Using the computer to perform operations on data.
Data processing (DP) system Systems concerned with transaction handling and record-keeping, usually for a particular functional area.
Data transfer rate The rate at which data are read/written from/to secondary storage to RAM.
Data warehouse A relational database created from existing operational files and databases specifically to help managers get the information they need to make informed decisions.
Data warehousing An approach to database management that involves moving existing operational files and databases from multiple applications to a data warehouse.
Database The integrated data resource for a computer-based information system
Database administrator (DBA) The individual responsible for the physical and logical maintenance of the database.
Database record Related data that are read from, or written to, the database as a unit.
Database software Software that permits users to create and maintain a database and to extract information from the database.
Debug To eliminate bugs in a program or system. (See alsobug.)
Decision support system (DSS) An interactive information system that relies on an integrated set of user-friendly hardware and software tools to produce and present information targeted to support management in the decision-making process. (Contrast with MIS and EIS.)
Decode To reverse the encoding process. (Contrast with encode.)
Decoder That portion of a processor's control unit that interprets instructions.
Dedicated keyboard port A port built into the system board specifically for the keyboard.
Dedicated mouse port A port built into the system board specifically for the cursorcontrol device.
Default options Preset software options that are assumed valid unless specified otherwise by the user.
Density The number of bytes per linear length or unit area of a recording medium.
Desktop The screen in Windows upon which icons, windows, a background, and so on are displayed.
Desktop film recorders An output device that permits the reproduction of high-resolution computer-generated graphic images on 35-mm film.
Desktop PC A non-portable personal computer that is designed to rest on the top of a desk. (Contrast with laptop PCand tower PC.)
Desktop publishing (DTP) Refers to the capability of producing typeset-quality camera-ready copy for publication from the confines of a desktop.
Desktop publishing software Software that allows users to produce near -typeset -quality copy for newsletters, advertisements, and many other printing needs, all from the confines of a desktop.
Destination application, clipboard The software application into which the clipboard contents are to be pasted. (contrast with source application).
Detailed system design That portion of the systems development process in which the target system is defined in detail.
Device controller Microprocessors that control the operation of peripheral devices.
Device driver software Software that contains instructions needed by the operating system to communicate with the peripheral device.
Dial-up line See switched line.
Dialog box A window that is displayed when the user must choose parameters or enter further information before the chosen menu option can be executed.
Digital camera A camera that records images digitally rather than on film.
Digital convergence The integration of computers, communications, and consumer electronics, with all having digital compatibility.
Digital signal Electronic signals that are transmitted as in strings of 1s and 0s. (See also analog signal.)
Digital videodisk (DVD) The successor technology to the CD-ROM that can store up to about 10 gigabytes.
Digitize To translate data or an image into a discrete format that can be interpreted by computers.
DIMM [Dual In-line Memory Module] A small circuit board, capable of holding several memory chips, that has a 64-bit data path and can be easily connected to a PC's system board. (Contrast with SIMM.)
Dimmed A menu option, which is usually gray, that is disabled or unavailable.
Digitizer tablet and pen A pressure-sensitive tablet with the same x-y coordinates as a computer-generated screen. The outline of an image drawn on a tablet with a stylus (pen) or puck is reproduced on the display.
Direct conversion An approach to system conversion whereby operational support by the new system is begun when the existing system is terminated.
Direct access See random access.
Direct-access file See random file.
Direct-access processing See random processing.
Direct-access storage device (DASD) A random-access secondary storage.
Disk, magnetic A secondary storage medium for random-access data storage available in permanently installed or interchangeable formats.
Disk address The physical location of a particular set of data or a program on a magnetic disk.
Disk caching A hardware/software technique in which frequently referenced disk-based data are placed in an area of RAM that simulates disk storage. (See also RAM disk.)
Disk cartridge An environmentally sealed interchangeable disk module that contains one or more hard disk platters.
Disk density The number of bits that can be stored per unit of area on the disk-face surface.
Disk drive, magnetic A magnetic storage device that records data on flat rotating disks. (Compare with tape drive, magnetic.)
Disk optimizer A program that reorganizes files on a hard disk to eliminate file fragmentation.
Diskette A thin interchangeable disk for secondary random-access data storage (same as floppy)
Docking station A device into which a notebook PC is inserted to give the notebook PC expanded capabilities, such as a high-capacity disk, interchangeable disk options, a tape backup unit, a large monitor, and so on.
Document file The result when work with an applications program, such as word processing, is saved to secondary storage.
Document icon A pictograph used by Windows within an application to represent a minimized document window.
Document window Window within an application window that is used to display a separate document created or used by that application.
Document-conversion program Software that converts files generated on one software package into a format consistent with another.
Domain expert An expert in a particular field who provides the factual knowledge and the heuristic rules for input to a knowledge base.
Domain name That portion of the Internet URL following the double forward slashes (//) that identifies an Internet host site.
DOS [Disk Operating System] See MS-DOS.
Dot pitch The distance between the centers of adjacent pixels on a display.
Dot-matrix printer A printer that arranges printed dots to form characters and images.
Double click Tapping a button on a point-and-draw device twice in rapid succession.
Download The transmission of data from a remote computer to a local computer.
Downsizing Used to describe the trend toward increased reliance on smaller computers for personal as well as enterprise-wide processing tasks.
Downtime The time during which a computer system is not operational.
DP See data processing.
Drag A point-and-draw device procedure by which an object is moved or a contiguous area on the display is marked for processing.
Drag-and-drop softwareSoftware that lets users drag ready-made shapes from application-specific stencils to the desired position on the drawing area to do drawings for flowcharting, landscaping, business graphics, and other applications.
Draw software Software that enables users to create electronic images. Resultant images are stored as vector graphics images.
Driver module The program module that calls other subordinate program modules to be executed as they are needed (also called a main program).
DTP See desktop publishing.
DVD See digital videodisk.
Dynamic RAM (DRAM)A type of RAM technology that requires stored data to be refreshed hundreds of times per second.