Cathode ray tube. See CRT.

CCITT. Short for Consultative Committee for International Telephone and Telegraphy, A United Nations standards organization responsible for setting international telecommunications standards.

CD ROM. An acronym for compact disk read-only memory. An optical disk on which data are encoded for retrieval by a laser. (See also Optical disk).

Cell. In a spreadsheet, the space representing the intersection of a row and column.

Cellular mobile radio. A technique for dividing a geographi Business systems analyst. A systems analyst who is in an organizational department other than the data-process-ing department. cal area into hexagonal-shaped cells. A local antenna within each cell is used to transmit via no interfering frequencies. As mobile radio users move from cell to cell, telephone calls continue uninterrupted while a central computer adjusts transmit and receive frequencies. Cellular mobile radio service is an alternative to the more limited single-antenna mobile-telephone services.

Central electronic complex. The processor and memory of a computer system along with some pathways for information to travel between the two.

Central processing unit. See CPU.

CGA. Short for color graphics adapter, an IBM video card that plugs into an expansion slot and provides 320- by 200-pixel resolution and a 16-color palette on the display screen. (See also EGA; VGA; XGA).

Channel. A pathway for the transmission of data or information to and from a computer or communication system.

Character map. A technique for dividing the display screen into a grid that is 25 rows high by 80 columns wide. Each location on the grid can correspond to a character, such as a letter, number, or punctuation mark. A ROM (read-only memory) stores each character as a pattern of dots.

Chart. Graphics or diagrams that display data or the relationships among data in pictorial form.

Charting program. A built-in component of spreadsheet programs. These programs are capable of transforming data that arc contained in their spread-sheet into charts -graphics or diagrams that display data or the relationships among data in pictorial form. Common chart types include bar, line, and pie charts.

Chip. A small piece of silicon or other semiconducting material containing an integrated circuit.

Circuit. (I) In a computer, an interconnected set of components that per-forms an electronic function. (2) In communications, an electrical connection between two nodes.

Circuit switching. A physical (electrical) connection between two nodes in a communication network that dedicates the entire bandwidth of that circuit until the connection is dropped. (See also Packet switching).

Class. In object-oriented programming, a generalized category that describes a group of objects that can exist within it. The class serves as the template from which specific objects are created.

Client. An end user or computer program that requests resources across a network.

Client/server computing. A combination of clients and servers that provides the framework for distributing files and databases across a network.

Clock. A computer circuit that uses regular electrical pulses to trigger, time, and synchronize various events within a computer.

Coaxial cable. A channel medium consisting of wire surrounded by a flexible metallic shielding.

COBOL. An acronym for Common Business Oriented Language. A high-level programming language that is used primarily for business-oriented applications.

Code. (l) A set of symbols, such as the dots and dashes of the Morse code, that represents another set of symbols, such as the letters of the alphabet. (2) The set of rules that defines the way in which bits can be ar-

ranged to represent numbers and letters. Example: ASCII. (3) To write a computer program in a specific programming language.

Collision. In a communications network, when two messages are transmitted at the same time, they will collide, resulting in a garbled transmission with neither message arriving at its destination intact.

Collision detection. A task performed in a network system to prevent two computers from transmitting at the same time and having the messages collide.

Command. An instruction that tells a computer to perform an operation.

Command-driven interface. Soil-ware that takes action as a result of the user typing single-letter, word, or line commands.

Command processor. A program that examines what you type when interacting with an operating system.

Communication. (l) A process by which information is exchanged between individuals through the use of a commonly agreed-onset of symbols. (2) From an engineering standpoint, the movement of electronic traffic from one point to another.

Communication channel. A transmission path for electrical or optical signals. All communication channels use the medium of electromagnetic waves, such as radio waves, light waves, and microwaves.

Communication processor. A device that interfaces a central computer to a number of terminals.

Communication server. A device that connects local-area networks (LANs) to wide-area (WANs) or telecommunication networks.

Communications software. Programs that enable a computer to connect to other computers and exchange information.

Communication system. A system that consists of senders (transmitters), physical channels, and receivers.

Compatibility. (I) The ability to connect different computer systems, devices, or software so they can work together. (2) The capability of different computer systems to process the same applications.

Compiler. A computer program (software) that reads a high-level program to (I) check it for spelling and grammar errors and (2) translate it into lower-level language instructions.

Component. In the computer industry, an elementary part, such as an integrated circuit, memory chip, or microprocessor, that can be connected to other parts to form larger systems.

Compression. Techniques for compacting information so that it requires less storage space.

Computer. An electronic device that can accept input, process it according to a set of instructions, store the instructions and the results of processing, and produce results as its output.

Computer-aided design (CAD). The use of a computer system to aid the process of design.

Computer-aided engineering (CAE). The use of a computer system to produce, analyze, test, and design systems and components.

Computer-aided manufacturing (CAM). The use of a computer system to assist in a manufacturing process.

Computer-aided software engineering (CASE). A set of tools to automate the tasks involved in designing and developing large-scale or complex software projects. Included are data dictionaries, diagram generators, prototyping tools, and consistency-checking tools.

Computer-assisted instruction (CAI). The use of a computer system to provide instruction and drill and practice in basic-computation and language skills.

Computer graphics. A broad term that refers to the methods and techniques used to draw pictures or images on display screens or on special graphic-printers and plotters.

Computer-integrated manufacturing (CIM). Computer-based systems in different company departments that integrate independent design, manufacturing, and administrative functions. For example, drafting accomplished on a CAD) system might be directly linked to a numerically controlled CAM factory machine tool.

Computer literacy. The knowledge and skills required to use a computer as a problem-solving tool.

Computer science. The science of problem-solving techniques using computers.

Computer systems analyst. systems analyst who is in the data-processing department and is concerned with the technical aspects of system design.

Computerization. The reshaping of society by the widespread adoption and use of computers.

Computerized information services. On-line databases to which subscribers can gain access via telephone lines.

Computerphobia. The fear of computers.

Concentrator. A device that combines data from several sources into a smaller number of channels for retransmission,

Concurrent program execution.

The execution of two or more programs at the same time. They actually take turns using the computer so rapidly that they give the illusion of operating concurrently.

Configuration. A set of computer equipment programmed and/or physically linked together to operate as a system.

Container object. An object that holds other objects so they can be easily stored, filed, or sent through electronic mail.

Control bus. An electrical pathway used to signal various parts of a computer when to transfer information and when the transfer is complete.

Control key. Akey that when pressed in combination with other keys generates control characters for use by a program. For example, pressing a control key in conjunction with the D key might mean delete a character in a word processing program.

Control structures. Statements in the program that control the order in which the instructions are executed. Examples include sequence, selection, looping, and case.

Control unit. The functional unit of the CPU that is responsible for retrieving instructions from memory, determining their type, and breaking each instruction into a series of simple, small steps or actions.

Coprocessor. A processor that adds additional functions to the central processor. Examples include math and graphics coprocessors.

Copy protection. A technique used by software developers to make a disk difficult, if not impossible, to copy.

CPU. An acronym for central processing unit. The part of the computer system that interprets and executes instructions, performs arithmetic and logic operations, and directs the input. storage, and output operations. Also called a processor.

CRT. An acronym for cathode ray tube. A type of screen found in television sets and computer displays in which an electron beam scans a phosphor-coated surface, leaving light or dark points of light (pixels) on the inside face of the screen. (See also Pixel).

Cursor. A visual aid on a display screen that indicates where the next symbol will appear, usually in the form of an arrow, blinking block, or blinking underline.

Cursor movement keys. Keys that move the cursor in a particular direction when pressed.

Cybernetics. The science of communication and control in living organisms and machines. It includes the study of messages as a means of controlling machinery and society, the development of automation, and the study of psychology and the nervous system. Cycle. A set of operations that is repeated regularly in the same sequence.

Cylinder. The imaginary surface composed of all the tracks that lie directly above and below one another on a multiple-platter disk pack.

D

Data. A general term meaning the facts, numbers, letters, and symbols processed by a computer or communication system to produce information. (See also Information).

Data bus. An electrical pathway over which data and instructions travel to and from the processor.

Data communications, the transfer of data or information between computer-related devices.

Data dictionary. (l) In system design, a listing of all the data elements and data structures within a system. (2) In a database system, a file that contains descriptions of and relationships among a collection of data.

Data-flow diagram. In systems analysis, a series of blocks that represents processes or procedures that are connected by flow lines.

Data independence. The ability of a database to exist independently of specific applications.

Data integrity. Techniques for protecting a database against invalid alteration or destruction.

Data model. A description of the way to structure and manipulate the data in a database. The structural part of the model specifies how data should be represented (e.g., tree, tables. and so on).

Data processing. A general term that stands for all the logical, arithmetic, and input/output operations that can be performed on data by a computer.

Data-processing analyst. A systems analyst who is in the data processing department of an organization and is concerned with the technical aspects of system design. Also called computer systems analyst.

Data-processing (DP) department. The combination of the information system and the people who support it. The DP department combines computer

and communication hardware and software with manual procedures and models for analysis, planning, control, and decision making.

Data security. Techniques for protecting a database against access or modification without authorization.

Data structure. An organizational scheme used to structure or organize data so that they can be stored, retrieved, and manipulated by a program. Exam-ples include records, lists, and arrays.

Database. (I) A collection of different types of data organized according to a structure that minimizes redundancies and facilitates the manipulation of the data. (2) A collection of one or more files treated as a whole unit.

Database management system (DBMS). Software that organizes, manipulates, and retrieves data stored in a database.

Database manager. Multiple files, their indexes, the relationships among data in the files, and a program to link the files and handle basic tasks. such as entering, modifying, retrieving, and printing data from the files. (See also File manager).

Database server. Software that services requests to a database across a network.

Database system. An information system that integrates a collection of data and makes it available to a wide variety of people in an organization.

Database transaction. A group of database modifications treated as a single unit.

Debug. The process of going through a program (software) or component (hardware) to remove errors.

Decimal number. Referring to the base 10 number system we normally use for arithmetic. Some early computers used decimal numbers instead of binary numbers.

Decision support software. Knowledge-based software that builds decision-making models.

Decision support system. Applications within MIS that directly support specific decision making.

Decode. To modify information from a computer-readable form into a form that people can read or use. (See also Encode).

Decryption. The decoding of a cryptic electronic transmission. (See also Encryption).

Dedicated. Something designed for a specific use, such as a leased line for data transmission or a computer intended only for word processing.

Default. An action or value that a computer automatically assumes unless a different action or value is specified.

Descending order. Arrangement of information in sequence from highest to lowest. (See also Ascending order).

Design review. The process of reexamining the proposed design with the intended users and other systems analysts and programming professionals.

Desktop publishing. The use of personal computers to prepare and print a wide variety of typeset- or near-typeset-quality documents. The process involves composing the text, manipulating graphics, making up or composing the document, and publishing the finished product on a laser printer or typesetter.

Detail documentation. Documentation that provides a programmer with sufficient information to write the program.

Device driver. Programs that interface with the operating system to control the operation of the hardware components of a personal computer system. The device driver is responsible for translating instructions from the application into commands the hardware understands.

Dialog box. A temporary window that contains choices when the program needs additional information from the user.

Dial-up line. The normal switched telephone line that is used as a transmission medium for communications.

Double in-line memory module (DIMM). A mini circuit board designed to accomodate surface-mounted memory chips. DIMMs plug into small sockets on the system.

Digital. Relating to the technology of communications and computers by which information is stored and transmitted in binary ones and zeros. (Sec also Analog).

Digital camera. A camera coupled with a processor used for encoding high)) detailed images, such as pictures or three-dimensional objects, into digital data.

Digital computer. A type of computer capable of representing binary digits by producing and sensing discrete on or off states represented by binary ones and zeros.

Digitizing. The process of translating analog data into digital data.

Direct conversion method. When changing from one computer system or method of operation to another, the old system or method is stopped and the new system or method is started immediately.

Direct-access file. A type of file organization scheme designed for processing records in an order other than sequential.

Also called a random-access file.

Direct source input. Data that are captured directly from their source without the requirement of a separate transcribing step. (See also Transcribed in-put).

Disk. A circular platter on which a magnetic or reflective coating is applied. Used for long-term storage of data.

Disk array. The combination and synchronization of multiple disk drives into one self-contained unit. A disk array features faster data access and higher data throughput than an equivalent-sized single disk drive.

Disk cartridge. Removable disks that are sealed in a container similar to a videotape cartridge.

Disk drive. A device that houses the motor to spin the disk and the read/write head for accessing and storing information on the disk.

Disk pack. A removable stack of hard disks joined together by a common spindle.

Display. A method or device for representing information that is output from a computer system. Usually found in the form of a cathode ray tube (CRT) or flat-panel display. (See also CRT; Flat-panel display).

Distributed computing. A type of processing that utilizes a number of small computers distributed throughout an organization.

Distributed database. A capability in which different pans of a database reside on physically separate computers. The goal is to access information without regard to where the data might be stored.

DMA. An acronym for direct-memory access. A technique by which the CPU is placed in a wait state while another device transfers data to or from memory at a high rate.

Document. Any text or collection of characters (letters, numbers, spaces, punctuation marks, and other symbols); usually associated with word processing and desktop-publishing applications.

Documentation. (I) The books, manuals, or tutorials that accompany a computer-related product. (2) Written specifications that are a part of the process of developing software.

DOS. An acronym for disk operating system. (See also Operating system).

Dot-matrix printer. A printer that uses a selected pattern of dots transferred by impact to produce images on paper.

Download. A method of sending a copy of data, such as a file, from a central location to a remote location and storing it there for future use.

DRAM. An acronym for dynamic random-access memory, a memory that is constantly refreshed with electrical pulses. Pronounced "dee-ram". Draw program. A graphics program that provides commands to create lines, circles, rectangles, and other shapes, as well as do freehand sketching, while allowing the objects created to be resized or moved around without affecting other objects. Exampies include MacDraw for the Macintosh and Windows Draw for MS-DOS computers. Duplex. A data communications term that indicates how many directions data can flow at one time. In half-duplex, data move in one direction at a time; in full-duplex, data move in two directions at a time.

E

EBCDIC. An acronym for Extended Binary-Coded Decimal Interchange Code. An eight-bit code designed by IBM that assigns binary digits to specific symbols. Used primarily by IBM computers.

Edit. To make changes in data, a program, or a document.

EGA. Short for enhanced graphics adapter, an IBM video board that plugs into an expansion slot and provides 640-by 350-pixel resolution and a 16-color palette on the display screen. (See also CG4. VGA).

Electroluminescent display (ELD). A display device that produces light through the application of electric current on a sensitive surface.

Electronic conference. A meeting that is conducted over an electronic network using terminals or personal computers.

Electronic data interchange (EDI). The computer-to-computer electronic transmission of standard documents such as invoices and purchase orders. EDI makes the translation of paper-based documents into and out of a generic form possible so that they can be transferred electronically among different computers.

Electronic mail. An electronic technology that handles the sending and receiving of messages.

Electronic mailbox. A tile stored on disk in which each record represents a message and serves as an interface for electronic mail.

Electronic marketplace. The buying and selling of information through information services and videotex services. Examples of services that can be subscribed to include Prodigy, The Source, CompuServe, Dialog, and Nexis.

Electronic pen. A pen that utilizes radio waves to communicate with a grid of wires underneath a liquid-crystal display screen. Radio waves are sent to the tip of the pen and returned for position analysis. Also called a stylus.

Electronic transaction. The electronic transfer of funds in lieu of conventional paper transactions, such as checks.

Electrostatic printer. A printer that uses electricity to transfer images onto specially coated paper.

Emulation. The imitation of one computer system or part of a computer system by another.

Encode. To modify information into a desired pattern for transmission or processing. (See also Decode).

Encryption. The coding of an electronic transmission for purposes of security or privacy. (See also Decryption).

End user. A person who uses a product, as opposed to a person who develops or markets the product.

End-user development. The use of tools, such as macros, program generators, or interface builders, by noncomputer specialists to develop applications that the end users will use.

Enterprise computing. Computer and communication technology that combines geographically dispersed office workers, computing resources, and information into a single integrated environment.

Erasable optical disk. An optical disk that uses lasers to read and write information to and from the disk, but also uses a magnetic material on the surface of the disk and a magnetic write head to achieve erasability.

Ergonomics. The science of the study of how people use tools to perform work and how they physically relate to their environment.

Error checking. In communications, software routines that identify and often correct erroneous data.

Execute. To run a computer program or part of a program.

Expanded memory. Bank-switched memory that expands the memory of a microprocessor beyond its one-megabyte limitation, (See also Bank switching; Extended memory).

Expansion slot. A series of sockets into which additional circuit boards can be plugged. Many personal computers and minicomputers use an "open architecture" by which additional hardware devices can easily be added to the system via expansion slots. (See also Architecture).

Expert system. A computer program that solves specialized

problems at the level of a human expert. Expert-system shell. development environment that uses rules or examples as its input but eliminates the need for programming.

Extendcd memory. Real memory that extends beyond the one-megabyte addressing limitation of a microprocessor. (See also expanded memory).

Facsimile. A method for electronically copying and transmitting an image.

Fault. A condition that causes a functional component to fail to operate in the required manner.

Fault-tolerant computer. A computer that uses redundant hardware or software components to prevent failure from disrupting the operation of the system. The system can continue processing while the fault) component is replaced or repaired.

Fiber-Distributed Data Interchange (FDDI). A token-based local-area network technology that operates at 100 million bits per second.

Fiber optics. Transmitting information by using infrared or visible light frequencies through glass libers.

Field. The smallest unit of named data that has meaning in a record. A field usually describes an attribute of the record, such as a name or address.

File. A collection of organized data stored as one complete unit for processing.

File manager. A single file, its indexes, and a program to handle basic tasks, such as entering, modifying, retrieving, and printing data from the file.

File server. A device that interfaces files or databases to a local-area network.

Firmware. Software that has been copied on integrated circuits, usually ROM (read-only memory).

First generation. Referring to computers of the period 1951-1958, which used vacuum tubes.

Fixed-length operations. The type of operations performed by a word-addressable computer.

Flat file. A single file consisting of rows (records) and columns (fields) of data that resemble a two-dimensional spreadsheet.

Flat-panel display. A display characterized by a thin panel consisting of rows and columns of pixels. Digital circuits feed signals to each row and column. For

example, sending a low voltage down a row while sending higher voltages across selected columns causes the pixels at the intersections to light up.

Floppy disk. A flexible plastic disk coated with a magnetic recording material.

Flowchart. A graphic representation used in the design phase of programming to represent the logic of a program or module. (See also System flowchart).

Form. (1) In database management systems, a display that identifies the names and characteristics of the fields within a record. (2) In printed materials. a structured document with spaces reserved for entering information.

Format. (1) The process of preparing a magnetic storage medium, such as a floppy disk, to store data in specified places (i.e., tracks and sectors). (2) The way information is physically organized on a display screen, printed page, or disk.

FORTRAN. Short for formula translator. A high-level computer programming language used primarily for scientific and engineering applications.

Fourth generation. Referring to computers of the period 1975 to the present, which use various forms of microprocessor and other VLSI chips. (See also Microprocessor; VLSI).

Fourth-generation language. A term that encompasses (1) presentation languages, such as query languages and report generators: (2) specialty languages, such as spreadsheets and database languages; (3) application generators that define, input, modify or update. and report data to build applications; and (4) very-high-level languages that arc used to generate application code. Often abbreviated as 4 GL.

Frame. (I) A basic unit of information (equivalent to one full screen) in a video-tex system. (2) The vertical section of magnetic tape that corresponds to one byte of data.

Frame buffer. In graphics, a special area of random-access memory that holds the contents of a screen display. The processor can perform manipulations on information in a frame buffer before it is displayed. Sometimes used interchangeably with the term bit map.

Freeware. Software that is given away free of charge. Freeware is often made available on electronic bulletin boards and through user groups.

Frequency. The rate at which a signal pattern is repeated.

Frequency-division multiplexing. The communication process of assigning a channel to several users on the basis of dividing the channel into different frequencies.

Front-end processor. A computer that handles ,communications between terminals and a central computer.

Full-duplex. A mode that allows two computers to send and receive data at the same time.

Full-text retrieval software. Software that allows text to be indexed, edited, annotated, linked, and searched for in an electronic document.

Function key. A key that tells a program to perform a specific action, usually labeled [F1] through [F-10 or F-12]. Pressing the [F1] key, for example, might invoke a help system.

Functional specification. A precise description of the functional requirements of a computer system.

G

Garbage in-garbage out. A term referring to information processing that has been distorted by invalid input.

Gas plasma display. A display device in which a gas. usually a mixture of neon and argon, is trapped between flat glass plates. A grid of electrodes permits the turning on and off of pixels.

Gate array. A standardized design for an integrated circuit consisting of a fixed number of logic gates that can be interconnected according to customer specifications.

Gateway. A device used to connect dissimilar networks.

General-purpose computer. A type of computer that can be programmed for a wide variety of tasks or applications.

General-purpose programs. Programs that are adaptable to a wide variety of tasks, such as word processing, spreadsheet, database management, graphics, and communications. Also called general-purpose application software.

Geographical information system (GIS). A system that digitizes maps and images of distributions of statistical data and displays them as graphics.

Gigabyte (GB). A unit of measure that is the equivalent of 2'°, or 1,073,741.824 bytes.

Graphical user interface. An interface that uses pictures and graphic symbols to represent commands, choices, or actions.

Graphics. The term encompassing several elements, including color, motion, and resolution, that together result in the ability of a computer to show line drawings, pictures, or animation on a display screen or printer.

Grayscale scanner. A scanner that is able to distinguish among levels of gray as well as black-and-white. By measuring the relative amount of reflected light, a grayscale scanner can translate points in the image into a code that represents the levels of gray at each point. Groupware. Application software that supports collaborative work and integrates electronic mail, conferencing, calendar and scheduling software: workflow software, which automates the routing of business processes and forms over a network; and document management software to handle the creating and revision of shared documents on a network. Guided-vehicle system. Robots that can find their way around a factory either by sensing guide wires embedded in the floor or through a vision system.

H

Hacker. A term for a person who gains access to computer systems without authorization.

Half-duplex. A mode that allows two computers to send and receive data, but only in one direction at a time. For example, if one computer is receiving data, it must wait until transmission is complete before sending data.

Handshaking. A procedure or protocol used to establish if two computers or a computer and a peripheral are ready to exchange information.

Handwriting recognition. The process of recognizing characters (e.g., letters, numbers, and punctuation) handwritten or printed on a display screen and translating them into digital codes that are redisplayed as text on the screen.

Hard automation. Dedicated equipment that can only perform a single operation under carefully controlled circumstances, for example, a factory assembly line that can automatically weld certain types of car parts.

Hard copy. Output from a computer system that is in the form of images recorded on paper or film.

Hard disk. A disk made of a rigid base, such as aluminum, and coated with a magnetic-oxide layer.

Hardware. The physical components associated with a computer or other system. (See also Software).

Hashing. A mathematical technique for assigning a unique number to each record in a file.

Heuristic methods. Exploratory methods for problem solving in which an evaluation is made of the progress toward the goal using a series of approximate

results. Sometimes associated with trial-and-error methods or rules of thumb. (See also Algorithm).

Hexadecimal number. A number system that uses a base of 16. Its symbols consist of 0,1,2,3,4, 5,6,7,8,9, A, B, C, D, E, and F. It is often used as a shorthand method for writing binary numbers. (See also Binary number; Decimal number).

Hierarchical model. A method for storing data in a database that structures data into an inverted tree in which records contain (1) a single root or master key field that identifies the type, location, or ordering of the records, and (2) a variable number of subordinate fields that define the rest of the data within a record.

Hierarchical network. A central controller coupled to a series of nodes (or subcontrollers). that are connected to several terminals or personal computers.

Hierarchy chart. A diagram that shows the interrelationships among program modules. Also called a structure chart.

High-level documentation. Documentation used by systems analysts to provide a picture of the overall structure of the system, including input, processing, storage, and output.

High-level language. A programming language that allows a programmer to specify instructions in English-like statements that are closer to the problem being solved than to the computer language in which the) are written.

Human factors. Those elements that pertain to the design of the software interface between people and computers. For example, the design of icons and windows is a human-factors concern.

Hybrid approach. An approach that enables the assembly of systems from two or more existing tools.

Hybrid computer. A type of computer designed for highly specialized tasks, which combines the features of both digital and analog computers.

Hypermedia. An extension of hypertext that includes graphics, video, sound, and music.

Hypertext. Electronic books in which an author can link information and create nonlinear paths through related material. Icon. picture on a display screen that represents a physical object, such as a file folder, memo, letter, in-basket. or wastebasket.

I

Image scanner. device that converts optically focused images, such as photographs or drawings, into digital images that can then be processed like any other digital data. A photoreceptor device is required to convert reflected light into digital images.

Immediate addressing.An addressing technique in which the contents of an address portion of an instruction contain an operand instead of an address. (See also Operand).

Impact printer.A printer that operates on the principle of a striking mechanism transferring an image through a ribbon onto paper.

Index. A list containing an entry for each record in a file organized in a certain way.

Index file.In a database, a file that keeps track of the addresses where records can be found.

Index sequential.A tile organization method that provides both sequential and direct-access capability.

Industrial work.Work involving the production of goods and services; it is often associated with blue-collar factory workers. Inference engine. The part of an expert system that performs the reasoning. (See also Expert system).

Information. (1) Data that have a context. (2) Data used in decision making.

Information explosion.Refers to the growing volume of information created by the increasingly complex society in which we live.

Information processing.The work that information systems perform, consisting of responding to input, processing that input according to instructions, and providing output.

Information revolution.(1) A term used to indicate the point at which modern society shifted from being an industrial society to being an information society. No agrced-on date. (2) The reshaping of economic, social, political, and technical structures resulting from the teaming of people and computers.

Information society.A society structured around the principles of information as a commodity and as a strategic resource.

Information system.A system that takes input, processes it, and produces information as output.

Information technology.A collective term for computer-and-communication hardware and system-and application-software.

Information theory.The branch of computer science that studies the properties of information and how it is measured.

Information work.Work involving professionals, managers, clerks, and administrators who produce information. Inheritance. In object-oriented programming, the passing along of certain behavior and structure from a class to its descendants. Inheritance allows new objects to be created from old ones.

Inkjet printer.A printer that uses a selected pattern of dots to form images that are transferred by spraying droplets of ink.

Input. (1) The use of a device to encode data. (2) The process of transferring data into a computer system.

Instruction.A basic unit of a program that specifies what action is to be performed on what data.

Instruction counter. A register used to store the address (location) of the next instruction to be executed by the CPU.

Instruction set.The unique set of software operations that comes with every processor and helps to define the architecture of the processor. (See also Architecture).

Integrated application software.Software that combines several applications under one consistent user interface.

Integrated circuit.A system of interrelated circuits packaged together on a single silicon chip.

Interactive. A computer system that provides response to all inquiries by the user.

Interface. The hardware and/or software necessary to interconnect components of a computer system or to connect one computer system to another.

Interface builder.A program that allows you to assemble a user interface, also called a front end, from a library of predefined graphic objects such as windows, buttons, and scroll bars. Interpreter. A computer program that translates an instruction into machine language, executes it, and then repeats the process for each instruction in a program until the program is finished.

Interrupt. A signal that causes a processor to suspend the instruction that it is currently executing and to transfer control to a special interrupt-handler program. Interrupts may occur because of an exception, such as an arithmetic overflow or data transfer error.

I/O port. An abbreviation for input/ output port. A device connected to a computer that allows the input or output of data and instructions. (See also Port).

Iterative prototyping. The process of building working models of the application, testing them, and modifying them in response to new ideas. (See also Prototyping).

J

Jargon. The vocabulary peculiar to a profession or group.

Joystick. A lever, pivoted to move in any direction, that controls the movement of a cursor on a display screen. Similar to a mouse but used mostly in game programs. (See also Cursor).

К

K. An abbreviation for 1024 bytes.

Key. A field in a file used to identify records for purposes of retrieval or sorting.

Key-to-disk or key-to-tape device. A device in which data are entered on a keyboard and directly recorded on a disk or tape.

Keyboard. Key switch technology coupled with electronic circuitry that is used to encode input data.

Key field. A field in a file used to identify records for purposes of retrieval or sorting.

Keypunch machine. An early type of input device in which data are entered on a keyboard and transcribed by punching combinations of holes into specially designed cards.

Kilobyte (KB). A unit of measure equal to 2'° or 1024 bytes. (See also TC).

Knowledge base. The collection of facts, data, beliefs, assumptions, and heuristic methods about a problem area.

Knowledge engineer. A systems designer who designs expert systems.

Knowledge representation. The formal method for representing facts and rules about the area under consideration in an expert system.

L

Laptop computer. A term used to indicate a portable computer that can be operated while on a persons lap. Laptop computers are battery powered in their normal operation.

Laser disk. See Optical disk.

Laser printer. A printer that uses a laser to record an impression on a drum or belt, which is then transferred to paper.

LCD. An acronym for liquid-crystal display. A liquid-filled display surface that, when electrically charged, creates images using ambient light. Typically used in watches, calculators, and portable computers.

LED. An acronym for light-emitting diode. A semiconductor device used as a display in watches, calculators, and instruments.

Life-cycle approach. An approach used in system design and software development that proceeds from definition to design and development to implementation.

Date: 2016-01-03; view: 958