G

G

G prefix See giga-.

G3 n. See PowerPC 750.

G4 n. See Power Macintosh.

GaAs n. See gallium arsenide.

gain n. The increase in the amplitude of a signal, as of voltage, current, or power, that is produced by a circuit. Gain can be expressed as a factor or in decibels. See also decibel.

gallium arsenide n. A semiconductor compound used in place of silicon to make devices that perform faster, require less power, and are more tolerant of temperature changes and radiation than those made with silicon. Also called: GaAs.

game n. See computer game.

Game Boy n. Nintendo Corporation s popular battery-powered, portable handheld gaming system first introduced in 1990 and updated frequently. Games are supplied on cartridges. The latest Game Boy, Game Boy Advance, features a 32-bit ARM CPU with embedded memory and a 2.9-inch TFT reflective screen with 240x160 resolution. See also computer game, TFT.

game card n. See ROM card.

game cartridge n. See ROM cartridge.

game console n. See console game.

Game Control Adapter n. In IBM personal computers and compatibles, a circuit that processes input signals at a game port. Devices such as joysticks and game paddles use potentiometers to represent their positions as varying voltage levels; the Game Control Adapter converts these levels to numbers using an analog-to-digital converter (ADC). See also analog-to-digital converter, game port, potentiometer.

GameCube n. Nintendo Corporation s console gaming system. It features a developer-friendly format and introduces 1T-RAM technology, which reduces delays to the main memory and the graphics LSI mixed memory. The microprocessor is a custom IBM Power PC Gekko featuring a secondary cache (Level One: Instruction 32 KB, Data 32 KB (8-way); Level Two: 256 KB (2-way)). Games are supplied on a GameCube game disc. See also computer game, console game. Compare Dreamcast, PlayStation, Xbox.

game pad n. An action-control input device used with arcade-type games played on PCs and game consoles such as Microsoft s Xbox, Nintendo s GameCube, Sega s Dreamcast, and Sony s PlayStation. A game pad, unlike a joystick, is meant to be held in a player s hands. Buttons on the game pad allow a player to control direction, speed, and other screen actions. Also called: joypad. Compare joystick.

game port n. In IBM personal computers and compatibles, an I/O port for devices such as joysticks and game paddles. The game port is often included with other I/O ports on a single expansion card. See the illustration. See also Game Control Adapter.

Game port.

gamer n. Refers to a person who plays games, sometimes role-playing games or trading card games; often a person who plays computer, console, arcade, or online games as a primary hobby or avocation.

game theory n. A mathematical theory, ascribed to John von Neumann, that considers strategy and probability in terms of competitive games in which all players have partial control and each seeks the most advantageous moves in relation to the others.

game tree n. A tree structure representing contingencies in a game and used by game developers for design purposes. Each node in a game tree represents a possible position (for example, the configuration of pieces on a chessboard) in the game, and each branching represents a possible move. See also computer game.

gamut n. The complete range of colors a display or printer is capable of producing. If a color falls outside the gamut of a device, it cannot be accurately displayed or printed from that device.

gamut alarm n. A feature in graphics programs that alerts the user if a chosen color will fall outside the currently selected gamut. See also gamut.

Gantt chart n. A bar chart that shows individual parts of a project as bars against a horizontal time scale. Gantt charts are used as a project-planning tool for developing schedules. Most project-planning software can produce Gantt charts.

gap n. See inter-record gap.

garbage n. 1. Incorrect or corrupted data. 2. Gibberish displayed on screen, either due to faulty hardware or software or because a program is unable to display a file s content. For example, an executable file is not meant to be displayed by a text editor and so is indecipherable on screen.

garbage collection n. A process for automatic recovery of heap memory. Blocks of memory that had been allocated but are no longer in use are freed, and blocks of memory still in use may be moved to consolidate the free memory into larger blocks. Some programming languages require the programmer to handle garbage collection. Others, such as Java, perform this task for the programmer. See also heap (definition 1).

garbage in, garbage out n. A computing axiom meaning that if the data put into a process is incorrect, the data output by the process will also be incorrect. Acronym: GIGO.

gas-discharge display n. A type of flat-panel display, used on some portable computers, containing neon between a horizontal and a vertical set of electrodes. When one electrode in each set is charged, the neon glows (as in a neon lamp) where the two electrodes intersect, representing a pixel. Also called: gas-plasma display. See also flat-panel display, pixel.

gas-plasma display n. See gas-discharge display.

gate n. 1. An electronic switch that is the elementary component of a digital circuit. It produces an electrical output signal that represents a binary 1 or 0 and is related to the states of one or more input signals by an operation of Boolean logic, such as AND, OR, or NOT. Also called: logic gate. See also gate array. 2. The input terminal of a field-effect transistor (FET). Also called: gate electrode. See also drain (definition 1), FET, MOSFET, source (definition 2). 3. A data structure used by 80386 and higher microprocessors to control access to privileged functions, to change data segments, or to switch tasks.

gate array n. A special type of chip that starts out as a nonspecific collection of logic gates. Late in the manufacturing process, a layer is added to connect the gates for a specific function. By changing the pattern of connections, the manufacturer can make the chip suitable for many needs. This process is very popular because it saves both design and manufacturing time. The drawback is that much of the chip goes unused. Also called: application-specific integrated circuit, logic array.

gated adj. 1. Transmitted through a gate to a subsequent electronic logic element. 2. Transmitted through a gateway to a subsequent network or service. For example, a mailing list on BITNET may be gated to a newsgroup on the Internet.

gate electrode n. See gate (definition 2).

gateway n. A device that connects networks using different communications protocols so that information can be passed from one to the other. A gateway both transfers information and converts it to a form compatible with the protocols used by the receiving network. Compare bridge.

gateway page n. See doorway page.

gating circuit n. An electronic switch whose output is either on or off, depending on the state of two or more inputs. For example, a gating circuit may be used to pass or not pass an input signal, depending on the states of one or more control signals. A gating circuit can be constructed from one or more logic gates. See also gate (definition 1).

gatored vb. To have been the victim of a hijackware program that seized control of an Internet shopping or surfing experience and caused the victim s browser to display ads and Web sites chosen by the program. Users may be gatored when they have unknowingly installed a program or plug-in with a hidden marketing agenda, which intrudes on the user s Web shopping to display ads or Web sites promoting competing products. The term gatored comes from the name of a plug-in that was one of the first hijackware products to be used by Web marketers. See also hijackware.

GB n. See gigabyte.

Gbps n. See gigabits per second.

GDI n. Acronym for Graphical Device Interface. In Windows, a graphics display system used by applications to display or print bitmapped text (TrueType fonts), images, and other graphical elements. The GDI is responsible for drawing dialog boxes, buttons, and other elements in a consistent style on screen by calling the appropriate screen drivers and passing them the information on the item to be drawn. The GDI also works with GDI printers, which have limited ability to prepare a page for printing. Instead, the GDI handles that task by calling the appropriate printer drivers and moving the image or document directly to the printer, rather than reformatting the image or document in PostScript or another printer language. See also bitmapped font, dialog box, driver, PostScript.

Gecko n. A cross-platform Web browsing engine introduced by Netscape in 1998, distributed and developed as open-source software through Mozilla.org. Designed to be small, fast, and modular, the Gecko engine supports Internet standards including HTML, cascading style sheets (CSS), XML, and the Document Object Model (DOM). Gecko is the layout engine in Netscape s Communicator software.

geek n. 1. Generally, a person who enjoys cerebral activities (such as wordplay or computer programming) more than the mainstream population does. Geeks in this sense increasingly claim the word with pride, but it may give offense when used by others, suggesting inadequacy in normal social relationships. 2. A computer expert or specialist. For issues of etiquette, see definition 1. Compare guru, techie, wizard.

GENA n. Acronym for General Event Notification Architecture. An extension to HTTP defined by an Internet Engineering Task Force (IETF) Internet-Draft and used to communicate events over the Internet between HTTP resources. Universal Plug and Play (UPnP) services use GENA to send XML event messages to control points.

gender bender n. See gender changer.

gender changer n. A device for joining two connectors that are either both male (having pins) or both female (having sockets). See the illustration. Also called: gender bender.

Gender changer.

General Event Notification Architecture n. See GENA.

General Inter-ORB Protocol n. See IIOP.

General Packet Radio Service n. See GPRS.

General Protection Fault n. The error condition that occurs in an 80386 or higher processor running in protected mode (such as Windows 3.1) when an application attempts to access memory outside of its authorized memory space or when an invalid instruction is issued. Acronym: GPF. See also protected mode.

General Public License n. The agreement under which software, such as the GNU (GNU s Not UNIX) utilities, is distributed by the Free Software Foundation. Anyone who has a copy of such a program may redistribute it to another party and may charge for distribution and support services, but may not restrict the other party from doing the same. A user may modify the program, but if the modified version is distributed, it must be clearly identified as such and is also covered under the General Public License. A distributor must also either provide source code or indicate where source code can be obtained. Acronym: GPL. Also called: copyleft. See also free software, Free Software Foundation, GNU.

general-purpose computer n. A computer that can perform any computational task for which software is available. A PC is a general-purpose computer.

general-purpose controller n. A controller that is designed for multiple uses. See also controller.

General-Purpose Interface Bus n. A bus developed for the exchange of information between computers and industrial automation equipment. The electrical definition of this bus has been incorporated into an IEEE standard. Acronym: GPIB. See also IEEE 488.

general-purpose language n. A programming language, such as Ada, Basic, C, or Pascal, designed for a variety of applications and uses. By contrast, SQL is a language designed to be used only with databases.

general-purpose register n. 1. A register within a microprocessor that is available for any use rather than being reserved, like a segment selector or stack pointer, for a specific use by the processor design or operating system. 2. Any digital circuit capable of storing binary data.

generation n. 1. A concept used to distinguish stored versions of a set of files. The oldest is called the grandfather, the next oldest is the father, and the newest is the son. 2. A concept used to distinguish among a process, another process that it initiates (its child), and the process that initiated it (its parent or the child s grandparent). See also process. 3. A category that distinguishes products, such as computers or programming languages, according to the technological advances they represent. See also computer.

generic icon n. An icon on a Macintosh screen that identifies a file only as a document or an application. Ordinarily the icon for an application will be specific to that application, and the icon for a document will be specific to the application that opens it. If a generic icon appears instead, the information that the Macintosh Finder uses to identify the application has been damaged. See also Finder, icon, Macintosh.

genetic algorithm n. A computational method for adapting problem solutions based on genetic aspects of evolution. Implementations typically use fixed-length text strings to represent information, together with a population of individuals that undergo crossover and mutation in order to find promising results. Genetic algorithms typically have three distinct stages: 1) Encoding of the potential solutions into bit strings that support the necessary variation, 2) mating and mutation algorithms that produce a new generation of individuals that recombine features of the parents, and 3) a fitness function that judges the results based on what is most appropriate for a potential solution to the problem. See also algorithm, genetic programming.

genetic programming n. A paradigm in which the principle of natural selection (whereby a biological entity whose structure is more fit for its environment than its peers produces descendants better able to survive) is applied to the creation of computer programs. Thus, genetic programming seeks to find and develop, from the set of all possible programs, code that is highly fit to solve problems, but not necessarily explicitly designed for a specific task. This inductive discovery method aims to mimic the natural selection process by developing computer code based on its adaptability and suitability. See also artificial intelligence.

Genie n. An online information service originally developed by General Electric (GE) Information Services as GEnie (General Electric network for information exchange); currently owned and provided by IDT Corporation as Genie (lowercase e). Genie provides business information, forums, home shopping, and news and can exchange e-mail with the Internet.

GEO n. See geostationary orbit satellite.

geographic information system n. An application or suite of applications for viewing and creating maps. Generally, geographic information systems contain a viewing system (sometimes allowing users to view maps with a Web browser), an environment for creating maps, and a server for managing maps and data for real-time online viewing. Acronym: GIS.

geometry n. The branch of mathematics that deals with the construction, properties, and relationships of points, lines, angles, curves, and shapes. Geometry is an essential part of computer-aided design and graphics programs.

GeoPort n. A fast serial input/output port on a range of Macintosh computers, including Macintosh Centris 660AV, Quadra 660AV, Quadra 840AV, or PowerMac. Any Macintosh-compatible serial device can be connected to a GeoPort, but with GeoPort-specific hardware and software the GeoPort can transmit data at up to 2 Mbps (megabits per second) and can handle voice, fax, data, and video transmission.

GEOS n. An operating system developed by Geoworks Corporation, used in some handheld devices. GEOS is designed to provide broad functionality in resource-constrained environments that have limited storage or memory capability, such as enhanced phones, some Internet access devices, and PDAs and other handheld computers.

geostationary adj. See geosynchronous.

geostationary orbit satellite n. A communications satellite that rotates with the earth and thus appears to remain fixed, or stationary, over a particular location. This travels in orbit 22,282 miles above the equator, where its period of rotation matches the earth s rotation. The service area, or footprint, of the satellite is approximately one-third of the earth s surface, so global satellite coverage can be achieved with three satellites in orbit. In a voice communication system, a round-trip to and from this satellite takes approximately 250 milliseconds. Satellite-based data communications are necessary for delivering high bandwidth options to rural areas. Acronym: GEO.

geosynchronous adj. Completing one revolution in the same time that the earth completes one rotation, as a communications satellite. Also called: geostationary.

germanium n. A semiconductor element (atomic number 32) that is used in some transistors, diodes, and solar cells but has been replaced by silicon in most applications. Germanium has a lower bias voltage than silicon but is more sensitive to heat (as in soldering).

get n. An FTP command that instructs the server to transfer a specified file to the client. See also FTP client, FTP commands, FTP server.

GFLOP n. See gigaflops.

GGA n. Acronym for Good Game All. GGA is often used in online and chat games at the conclusion of play. See also role-playing game.

ghost1 n. 1. A dim, secondary image that is displaced slightly from the primary image on a video display (due to signal reflection in transmission) or on a printout (due to unstable printing elements). 2. An abandoned or no-longer-maintained Web site that remains accessible to visitors.

ghost2 vb. 1. To produce a duplicate, such as duplicating an application in memory. See also screen saver. 2. To display an option on a menu or on a submenu in faint type to show that it cannot be selected at the present time.

ghosting n. See burn in (definition 2).

giant magnetoresistive head n. A type of hard-disk head developed by IBM and based on a physical property known as the giant magnetoresistive effect. Discovered by European scientists in the late 1980s, the giant magnetoresistive effect, or GMR, produces large resistance changes in magnetic fields when various metallic materials are sandwiched together in thin, alternating layers. When incorporated into disk heads, GMR technology allows for very dense data storage currently, as much as 11.6 billion bits per square inch, or the equivalent of more than 700,000 typewritten pages. Acronym: GMR. See also head.

.gif n. The file extension that identifies GIF bit map images. See also GIF.

GIF n. 1. Acronym for Graphics Interchange Format. A graphics file format developed by CompuServe and used for transmitting raster images on the Internet. An image may contain up to 256 colors, including a transparent color. The size of the file depends on the number of colors actually used. The LZW compression method is used to reduce the file size still further. See also LZW compression, raster graphics. 2. A graphic stored as a file in the GIF format.

GIF animation n. A file containing a series of graphics that are displayed in rapid sequence in a Web browser to appear as though they are a moving picture.

giga- prefix 1. One billion (1000 million, 109). 2. In data storage, 1024 1,048,576 (230) or 1000 1,048,576. See also gigabyte, gigaflops, gigahertz, kilo-, mega-.

Gigabit Ethernet n. The IEEE standard dubbed 802.3z, which includes support for transmission rates of 1 Gbps (gigabit per second) 1000 Mbps (megabits per second) over an Ethernet network. The usual Ethernet standard (802.3) supports only up to 100 Mbps. Compare Ethernet/802.3.

gigabit over copper n. See Cat 5 cable.

gigabits per second n. A measurement of data transfer speed, as on a network, in multiples of 1,073,741,824 (230) bits. Acronym: Gbps.

gigabyte n. 1. 1024 megabytes (1024 x 1,048,576 [230] bytes). 2. One thousand megabytes (1000 x 1,048,576 bytes). Acronym: GB.

gigaflops n. A measure of computing performance: one billion (1000 million) floating-point operations per second. Acronym: GFLOP. See also floating-point operation.

gigahertz n. A measure of frequency: one billion (1000 million) cycles per second.Abbreviation: GHz.

gigaPoP n. Short for gigabit Point of Presence.. A point of access for Internet2 (and possibly other high-speed networks) that supports data transfer speeds of at least 1 Gbps. Approximately 30 gigaPoPs are located at various points across the United States.

GIGO n. See garbage in, garbage out.

GIMP n. Acronym for GNU Image Manipulation Program. A free and expandable graphics program for image creation and photo manipulation. GIMP is available for various UNIX-related platforms, including Linux and Mac OS X.

GIOP n. See IIOP. Short for General Inter-ORB Protocol.

GIS n. See geographic information system.

GKS n. See Graphical Kernel System.

glare filter n. A transparent mask placed over the screen of a video monitor to reduce or eliminate light reflected from its glass surface.

glitch n. 1. A problem, usually minor. 2. A brief surge in electrical power.

global adj. Pertaining to an entire document, file, or program rather than to a restricted segment of it. Compare local, local variable.

global assembly cache n. A machine-wide code cache, introduced with Microsoft s .NET systems, that stores assemblies specifically installed to be shared by many applications on the computer. Applications deployed in the global assembly cache must have a strong name. Acronym: GAC. See also assembly cache, strong name.

global catalog n. A directory Windows database that applications and clients can query to locate any object in a forest. The global catalog is hosted on one or more domain controllers in the forest. It contains a partial replica of every domain directory partition in the forest. These partial replicas include replicas of every object in the forest, as follows: the attributes most frequently used in search operations and the attributes required to locate a full replica of the object. See also Active Directory, attribute, domain controller, forest, replication.

globally unique identifier n. In the Component Object Model (COM), a 16-byte code that identifies an interface to an object across all computers and networks. Such an identifier is unique because it contains a time stamp and a code based on the network address hardwired on the host computer s LAN interface card. These identifiers are generated by a utility program. Acronym: GUID.

global operation n. An operation, such as a search and replace, that affects an entire document, program, or other object such as a disk.

Global Positioning System n. See GPS.

global search and replace n. A search-and-replace operation that finds and changes all instances of the selected string throughout a document. See also search and replace.

Global System for Mobile Communications n. See GSM.

global universal identification n. An identification scheme in which only one name is associated with a particular object; this name is accepted across platforms and applications. Acronym: GUID. See also globally unique identifier.

global variable n. A variable whose value can be accessed and modified by any statement in a program, not merely within a single routine in which it is defined. See also global. Compare local variable.

GMR n. See giant magnetoresistive head.

GNOME n. Acronym for GNU Network Object Model Environment. A popular open-source desktop environment for UNIX and UNIX-based operating systems such as Linux. GNOME provides a GUI desktop interface and basic applications that correspond to those found with Microsoft Windows or the Macintosh operating system. By providing a mainstream environment and familiar desktop appearance GNOME is intended to make UNIX easier for users. Development of GNOME is overseen by the GNOME Foundation, an association of computer industry companies and organizations with interests in the UNIX operating system. GNOME and KDE are leading contenders for consideration as a Linux desktop standard. See also KDE.

gnomon n. In computer graphics, a representation of the three-dimensional (x-y-z) axis system.

GNU n. Acronym for GNU s Not UNIX. A collection of software based on the UNIX operating system maintained by the Free Software Foundation. GNU is distributed under the GNU General Public License, which requires that anyone who distributes GNU or a program based on GNU may charge only for distribution and support and must allow the user to modify and redistribute the code on the same terms. See also Free Software Foundation, General Public License. Compare Linux.

GNU Image Manipulation Program n. See GIMP.

Gnutella n. A file-sharing protocol that forms the basis of a number of peer-to-peer networking products. Gnutella forms a loose decentralized network with each user able to see and access all shared files of other Gnutella users. Unlike Napster, Gnutella does not require a central server, and any file type can be exchanged. Gnutella was originally developed by researchers at America Online s Nullsoft group but the original implementation of the protocol was never publicly released. An open-source Gnutella preview appeared that resulted in a number of variations becoming available. See also Napster.

Godwin s Law n. As originally proposed by Internet activist Michael Godwin, the theory that as an online discussion grows longer, a comparison involving Nazis or Hitler will inevitably be made. When a participant in an online discussion resorts to invoking such a comparison, other participants might cite Godwin s Law to indicate both that the person has lost the argument and that the discussion has continued too long.

Good Times virus n. A purported e-mail virus alluded to in a warning that has been propagated widely across the Internet, as well as by fax and standard mail. The letter claims that reading an e-mail message with the subject Good Times will cause damage to the user s system. In fact, it is currently impossible to harm a system by reading an e-mail message, although it is possible to include a virus in a file that is attached to an e-mail message. Some consider the chain letter itself to be the virus that wastes Internet bandwidth and the reader s time. Information on such hoaxes and on real viruses can be obtained from CERT (http://www.cert.org/). See also urban legend, virus.

Gopher or gopher n. An Internet utility for finding textual information and presenting it to the user in the form of hierarchical menus, from which the user selects submenus or files that can be downloaded and displayed. One Gopher client may access all available Gopher servers, so the user accesses a common Gopherspace. The name of the program is a three-way pun: it is designed to go for desired information; it tunnels through the Internet and digs the information up; and it was developed at the University of Minnesota, whose athletic teams are named the Golden Gophers. Gopher is being subsumed by the World Wide Web.

Gopher server n. The software that provides menus and files to a Gopher user. See also Gopher.

Gopher site n. A computer on the Internet on which a Gopher server runs. See also Gopher, Gopher server.

Gopherspace n. The total set of information on the Internet that is accessible as menus and documents through Gopher. See also Gopher.

GOSIP n. Acronym for Government Open Systems Interconnection Profile. A U.S. government requirement that all of its new network purchases comply with the ISO/OSI standards. GOSIP went into effect on August 15, 1990, but was never fully implemented and was replaced by POSIT.

GOTO statement n. A control statement used in programs to transfer execution to some other statement; the high-level equivalent of a branch or jump instruction. Use of GOTO statements is generally discouraged because they make it difficult not only for a programmer to trace the logic of a program but also for a compiler to generate optimized code. See also branch instruction, jump instruction, spaghetti code.

.gov n. In the Internet s Domain Name System, the top-level domain that identifies addresses operated by government agencies. The domain name .gov appears as a suffix at the end of the address. In the United States, only nonmilitary federal government agencies may use the .gov domain. State governments in the United States use the top-level domain of .state.us, with .us preceded by the two-letter abbreviation for the state, or just .us; other regional governments in the United States are registered under the .us domain. See also DNS (definition 1), domain (definition 3), .state.us, .us. Compare .com, .edu, .mil, .net, .org.

Government Open Systems Interconnection Profile n. See GOSIP.

GPF n. See General Protection Fault.

GPIB n. See General-Purpose Interface Bus.

GPL n. See General Public License.

GPRS n. Acronym for General Packet Radio Service. A third-generation enhancement to the Global System for Mobile Communications (GSM), which supports non-voice applications such as Web browsing and other servicing requiring transfer of data packets without limits in message size. Systems using the service can be immediately connected when needed and therefore seem to the users to be always on. See also GSM, TDMA.

GPS n. Acronym for Global Positioning System. A radio navigation system developed by the U.S. Department of Defense that uses a constellation of 24 earth satellites, which are monitored by ground-based control stations, to provide precise, continuous worldwide positioning and timing information. GPS offers two services: a public Standard Positioning Service that provides positioning data accurate to within 100 meters horizontally and 156 meters vertically and time accurate to within 340 nanoseconds; and a Precise Positioning Service, principally for government and military use, with positioning data accurate to within 22 meters horizontally and 27.7 meters vertically and time accurate to within 100 nanoseconds. See also GPS receiver.

GPS receiver n. A device that includes an antenna, a radio receiver, and a processor for use with the worldwide GPS (Global Positioning System). A GPS receiver uses position and time information from four GPS satellites to calculate precise information about its current location, its speed of travel, and the current time. A portable GPS receiver may be a stand-alone device or a plug-in unit for use with a portable computer. GPS receivers are used for scientific work, such as surveying, mapping, and studies of volcanoes, as well as for land, sea, and air navigation. On the consumer front, they are used in outdoor activities such as hiking and sailing and in cars to provide location, destination, and traffic information. See also GPS.

grabber n. 1. A device for capturing graphical image data from a video camera or another full-motion video source and putting it into memory. Also called: frame grabber, video digitizer. 2. Any device for capturing data. 3. Software that takes a snapshot of the currently displayed screen image by transferring a portion of video memory to a file on disk. 4. In some graphics-based applications, a special type of mouse pointer.

graceful exit n. The methodical termination of a process, even under error conditions, that allows the operating system or parent process to regain normal control, leaving the system in a state of equilibrium. This is expected behavior. See also fail-soft system.

grade n. In communications, the range of frequencies available for transmission on a single channel. For example, voice-grade telephone frequencies range from about 300 hertz (Hz) through 3400 Hz.

grade of service n. The probability that a user of a shared communications network, such as a public telephone system, will receive an all channels busy signal. The grade of service is used as a measure of the traffic-handling ability of the network and is usually applied to a specific period, such as the peak traffic hour. A grade of service of 0.002, for example, assumes that a user has a 99.8 percent chance that a call made during the specified period will reach its intended destination.

gradient n. A smooth progression of colors and shades, usually from one color to another color, or from one shade to another shade of the same color.

Graffiti n. A software application developed by Palm to allow handwriting recognition on personal digital assistants (PDAs). Graffiti contains preprogrammed shapes for each letter, which users of the application must match as closely as possible when writing. Text is written directly onto the PDA s display screen using a stylus. The Graffiti application then passes the translated letter to the PDA s application.

grafPort n. A structure used on the Apple Macintosh to define a graphics environment with its own pen size, font, fill patterns, and so on. Each window has a grafPort, and grafPorts can be used to send graphics to off-screen windows or files.

graftal n. One of a family of geometric forms, similar to fractals but easier to compute. Graftals are often used in the special-effects industry to create synthetic images of structures such as trees and plants. See also fractal.

grammar checker n. A software accessory that checks text for errors in grammatical construction.

Grammar Specification Language n. See GSL.

grandfather n. See generation (definition 1).

grandfather/father/son adj. See generation (definition 1).

grandparent n. See generation (definition 2).

granularity n. A description, from coarse to fine, of a computer activity or feature (such as screen resolution, searching and sorting, or time slice allocation) in terms of the size of the units it handles (pixels, sets of data, or time slices). The larger the pieces, the coarser the granularity.

graph n. 1. In programming, a data structure consisting of zero or more nodes and zero or more edges, which connect pairs of nodes. If any two nodes in a graph can be connected by a path along edges, the graph is said to be connected. A subgraph is a subset of the nodes and edges within a graph. A graph is directed (a digraph) if each edge links two nodes together only in one direction. A graph is weighted if each edge has some value associated with it. See also node (definition 3), tree. 2. See chart.

Graphical Device Interface n. See GDI.

graphical interface n. See graphical user interface.

Graphical Kernel System n. A computer graphics standard, recognized by ANSI and ISO, that specifies methods of describing, manipulating, storing, and transferring graphical images. It functions at the application level rather than the hardware level and deals with logical workstations (combinations of input and output devices such as keyboard, mouse, and monitor) rather than with individual devices. Graphical Kernel System was developed in 1978 to handle two-dimensional graphics; the later modification, GKS-3D, extended the standard to three-dimensional graphics. Acronym: GKS. See also ANSI, ISO.

graphical user interface n. A visual computer environment that represents programs, files, and options with graphical images, such as icons, menus, and dialog boxes, on the screen. The user can select and activate these options by pointing and clicking with a mouse or, often, with the keyboard. A particular item (such as a scroll bar) works the same way for the user in all applications, because the graphical user interface provides standard software routines to handle these elements and report the user s actions (such as a mouse click on a particular icon or at a particular location in text, or a key press); applications call these routines with specific parameters rather than attempting to reproduce them from scratch. Acronym: GUI.

graphic character n. Any character that is represented by a visible symbol, such as an ASCII character. A graphic character is not the same as a graphics character. Compare graphics character.

graphic limits n. On a computer screen, the boundary of a graphical image in a graphics software program, including all the area enclosed within the graphic. In some graphics environments the limits of a graphic consist of the smallest rectangle that can completely enclose it, called its bounding rectangle or bounding box.

graphics accelerator n. A video adapter that contains a graphics coprocessor. A graphics accelerator can update the video display much more quickly than the CPU can, and it frees the CPU for other tasks. A graphics accelerator is a necessity for modern software such as graphical user interfaces and multimedia applications. See also graphics coprocessor, video adapter.

graphics adapter n. A video adapter capable of displaying graphics as well as alphanumeric characters. Almost all video adapters in common use today are graphics adapters.

graphics card n. See video adapter.

graphics character n. A character that can be combined with others to create simple graphics, such as lines, boxes, and shaded or solid blocks. See the illustration. Compare graphic character.

Graphics character. Box built up from line graphics characters.

graphics controller n. The part of the EGA and VGA video adapters that allows the computer to access the video buffer. See also EGA, VGA.

graphics coprocessor n. A specialized microprocessor, included in some video adapters, that can generate graphical images such as lines and filled areas in response to instructions from the CPU, freeing the CPU for other work.

graphics data structure n. A data structure that is designed specifically for representing one or more elements of a graphical image.

graphics engine n. 1. A display adapter that handles high-speed graphics-related processing, freeing the CPU for other tasks. Also called: graphics accelerator, video accelerator. 2. Software that, based on commands from an application, sends instructions for creating graphic images to the hardware that actually creates the images. Examples are Macintosh QuickDraw and Windows Graphics Device Interface (GDI).

graphics export component n. A technology developed by Apple for creating, editing, publishing, and viewing multimedia content. The graphics export component provides an application programming interface that enables a QuickTime player to export still images into a variety of file formats.

graphics import component n. A technology developed by Apple for creating, editing, publishing, and viewing multimedia content. The graphics import component provides an application programming interface that enables a QuickTime player to import still images from a variety of file formats.

Graphics Interchange Format n. See GIF.

graphics interface n. See graphical user interface.

graphics mode n. 1. On computers such as the IBM PC, the display mode in which lines and characters on the screen are drawn pixel by pixel. Because graphics mode creates images from individual dots on the screen, programs have more flexibility in creating images than they do in text (or character) mode. Thus, the computer is able to display a mouse pointer as an arrowhead or other shape rather than as a blinking square or rectangle, and it can display character attributes, such as boldface and italics, as they will appear in print rather than using conventions such as highlighting, underlining, or alternate colors. Compare text mode. 2. A particular set of color and resolution values, often related to a particular video adapter, such as VGA color with 16 colors and 640 x 480 pixels on the screen. See also high resolution, low resolution, resolution (definition 1).

graphics port n. See grafPort.

graphics primitive n. A drawing element, such as a text character, an arc, or a polygon, that is drawn and manipulated as a single unit and is combined with other primitives to create an image. Compare entity.

graphics printer n. A printer, such as a laser, ink-jet, or dot-matrix impact printer, that can produce graphics formed pixel by pixel and not merely text characters. Nearly all printers presently used with personal computers are graphics printers; daisy-wheel printers are the exception. Compare character printer.

graphics processor n. See graphics coprocessor.

graphics tablet n. A device used to input graphics position information in engineering, design, and illustration applications. A flat rectangular plastic board is equipped with a puck or a pen (also called a stylus) and sensing electronics that report the position of the puck or stylus to the computer, which translates that data into a cursor position on the screen. Also called: digitizing tablet. See also puck, stylus.

graphics terminal n. A terminal capable of displaying graphics as well as text. Such terminals usually interpret graphics control commands rather than receiving streams of already-processed pixels.

Graphite n. An alternate appearance option in Mac OS X that features a gray interface with more subtle highlights than the colorful standard Aqua appearance. See also Aqua.

Gray code n. See cyclic binary code.

gray market n. Resellers and other sources for hardware and software that obtain their inventory from distributors other than those authorized by the manufacturer. Gray market transactions may involve items that wholesalers purchase at discount and resell at higher prices, or they may refer to purchases made when sudden spikes in demand cannot be satisfied through normal distribution channels. On a more unsavory front, gray market transactions can also illegally involve stolen or counterfeit hardware, such as CPU chips and software packages.

gray scale n. A sequence of shades ranging from black through white, used in computer graphics to add detail to images or to represent a color image on a monochrome output device. Like the number of colors in a color image, the number of shades of gray depends on the number of bits stored per pixel. Grays may be represented by actual gray shades, by halftone dots, or by dithering. See also dithering, halftone.

greater than adj. See relational operator.

greater than or equal to adj. See relational operator.

Great Plains n. Microsoft Corporation s suite of business solution applications for finance, accounting, and management. Microsoft acquired the Great Plains applications in December 2000, when it purchased Great Plains Software, which had originally developed the suite of business accounting and management solutions. Great Plains Business Solutions include applications for accounting and finance, customer relations management, e-commerce, human resources, manufacturing, project accounting, and supply-chain management.

Great Renaming n. The changeover to the current system of Usenet hierarchies throughout the Internet. Before the Great Renaming, which took place in 1985, nonlocal newsgroup names had the form net.*; for example, a group that carried source code, formerly named net.sources, was renamed comp.sources.misc. See also local newsgroups, newsgroup, traditional newsgroup hierarchy, Usenet.

greeking n. 1. The use of gray bars or other graphics to represent lines of characters too small to be drawn legibly on a screen at the chosen resolution, such as when viewing the layout of a whole page or pair of facing pages. 2. The use of nonsense words to represent the text of a document in design samples. A garbled Latin text beginning Lorem ipsum dolor sit amet is traditionally used for this purpose. Greeking does not involve substituting the Greek alphabet for the Roman one.

greek text n. See greeking.

Green Book n. A specifications book written by the Sony and Philips Corporations, covering the CD-I (compact disc-interactive) technology. See also CD-I. Compare Orange Book (definition 2), Red Book (definition 2).

green PC n. A computer system designed to conserve energy. For example, some computers shut off power to nonessential systems when no input has been detected for a certain amount of time, a condition known as sleep mode. Green PCs may also be distinguished by the use of minimal packaging materials and replaceable components, such as toner cartridges, that are recyclable.

Gregorian calendar n. The calendar used today in the Western world, introduced by Pope Gregory XIII in 1582 to replace the Julian calendar. To approximate better the length of the astronomical year (365.2422 days), years divisible by 100 are leap years only if they are also divisible by 400 (thus, 2000 was a leap year, but 1900 was not). To correct the error accumulated since A.D. 1, 10 days were dropped from October 1582; however, Britain and the American colonies did not adopt the Gregorian calendar until 1752 and had to remove 11 days then. Because the Gregorian calendar uses several rules for calculating leap years, systems based on algorithms that did not correctly determine that the year 2000 was a leap year might have encountered difficulties after February 28, 2000. Compare Julian calendar.

grep1 n. Acronym for global regular expression print. A UNIX command used to search a file or files by keyword.

grep2 vb. To search text, especially with the UNIX grep utility.

grid n. 1. Two sets of lines or linear elements at right angles to each other. 2. A spreadsheet is a grid of rows and columns; a graphics screen is a grid of horizontal and vertical lines of pixels. 3. In optical character recognition, a grid is used for measuring or specifying characters. See also Cartesian coordinates.

gridlines n. 1. Lines across a page in a graphics program that correspond to intervals on a ruler. 2. In many word-processing and spreadsheet programs, thin lines that indicate the cell boundaries in a table. 3. Lines you can add to a chart that make it easier to view and evaluate data. Gridlines extend from the tick marks on an axis across the plot area. Gridlines do not print when you print a document.

grok vb. To understand deeply and appreciatively. The term comes from Robert A. Heinlein s novel Stranger in a Strange Land, where it is also a Martian word for to drink and implies the kind of devoted interest that a Martian native of a dry planet would have in water. Hackers often use it (for example, in Internet discussions) in reference to computer expertise. See also cyberpunk.

ground n. A conducting path from an electric circuit to earth or to a conducting body serving in place of earth, usually used as a safety device. See also grounding.

grounding n. The connection of sections of an electrical circuit to a common conductor, called the ground, which serves as the reference for the other voltages in the circuit. The ground conductor on installed circuit boards is usually connected to the chassis, or metal frame, holding the electronic parts; the chassis is in turn usually connected to the third (round) prong on the power plug, which connects to a ground circuit that is, in fact, connected to the earth. This is important to avoid creating a shock hazard.

group1 n. A collection of elements that can be treated as a whole, such as a collection of records in a database report, or a collection of objects that can be moved and transformed as a single object in a drawing program. In various multiuser operating systems, a group is a set of user accounts, sometimes called members; privileges can be specified for the group, and each member will then have those privileges. See also built-in groups. Compare local group, user account.

group2 vb. In a drawing program, to transform a number of objects into a group. See also drawing program.

Group Policy Object n. A collection of Group Policy settings that are essentially the documents created by the Group Policy snap-in, a utility in Microsoft Windows 2000. These settings are stored at the domain level and affect users and computers contained in sites, domains, and organizational units. Acronym: GPO.

groupware n. Software intended to enable a group of users on a network to collaborate on a particular project. Groupware may provide services for communication (such as e-mail), collaborative document development, scheduling, and tracking. Documents may include text, images, or other forms of information.

grovel vb. 1. To search or do other work at great length without apparent progress. Some programs grovel over a whole input file before they begin to produce output. A programmer may have to grovel through manuals in search of documentation on a particular command, or through code in search of a bug. 2. To post a plea for some favor to a newsgroup.

grunge n. See dead code.

GSL n. Acronym for Grammar Specification Language. A grammar description format used by VoiceXML applications and other speech recognition systems. GSL was developed by Nuance and supports a number of XML-based speech editing and voice-browsing applications.

GSM n. Acronym for Global System for Mobile Communications. A digital cellular phone technology first deployed in 1992. In 2000, GSM was the predominant phone technology in Europe, and was used by 250 million subscribers worldwide. GSM phones offer a removable smart card containing subscriber account information. This card can be transferred from phone to phone quickly and easily, allowing the user to access his account from any phone in the system. Various enhancements to the GSM system allow increased Web browsing and data transfer options. See also GPRS, TDMA.

guest n. A common name for a login account that can be accessed without a password. BBSs and service providers often maintain such an account so that prospective subscribers can sample the services offered.

guest account n. An account used to log onto a system or domain where the user does not have access. Generally, resources and access are severely limited. On Windows NT technology, this account is built in to all domains. See also domain.

GUI n. See graphical user interface.

GUID n. See globally unique identifier, global universal identification.

GUID partition table n. A disk-partitioning scheme that is used by the eXtensible Firmware Interface (EFI) in Itanium-based computers. A GUID partition table offers more advantages than master boot record (MBR) partitioning because it allows up to 128 partitions per disk, provides support for volumes up to 18 exabytes in size, allows primary and backup partition tables for redundancy, and supports unique disk and partition IDs (GUIDs). Acronym: GPT. See also eXtensible Firmware Interface, Itanium, master boot record.

gunzip n. A GNU utility for decompressing files compressed with gzip. See also GNU, uncompress. Compare gzip.

guru n. A technical expert who is available to help solve problems and to answer questions in an intelligible way. See also techie, wizard (definition 1).

gutter n. The blank area between two or more columns of text or between two facing pages in a publication.

gzip n. A GNU utility for compressing files. See also compress2, GNU. Compare gunzip.



Microsoft Computer Dictionary
MicrosoftВ® Computer Dictionary, Fifth Edition
ISBN: 0735614954
EAN: 2147483647
Year: 2002
Pages: 36

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net