MICROSOFT Computer Dictionary, Fifth Edition

Microsoft Computer Dictionary, Fifth Edition

n. In mathematics, an item that is multiplied in a multiplication problem; for example, 2 and 3 are factors in the problem 2 x 3. The prime factors of a number are a set of prime numbers that, when multiplied together, produce the number.

factorial

n. Expressed as n! (n factorial), the result of multiplying the successive integers from 1 through n; n! equals n x (n – 1) x (n – 2) x ... x 1.

failback

n. In a cluster network system (one with two or more interconnected servers), the process of restoring resources and services to their primary server after they have been temporarily relocated to a backup system while repairs were implemented on the original host. See also cluster, failover.

failover

vb. In a cluster network system (one with two or more interconnected servers), to relocate an overloaded or failed resource, such as a server, a disk drive, or a network, to its redundant, or backup, component. For example, when one server in a two-server system stops processing because of a power outage or other malfunction, the system automatically fails over to the second server, with little or no disruption to the users. See also cluster, failback.

fail-safe system

n. A computer system designed to continue operating without loss of or damage to programs and data when part of the system breaks down or seriously malfunctions. Compare fail-soft system.

fail-soft system

n. A computer system designed to fail gracefully over a period of time when an element of hardware or software malfunctions. A fail-soft system terminates nonessential functions and remains operating at a diminished capacity until the problem has been corrected. Compare failsafe system.

failure

n. The inability of a computer system or related device to operate reliably or to operate at all. A common cause of system failure is loss of power, which can be minimized with a battery-powered backup source until all devices can be shut down. Within a system, electronic failures generally occur early in the life of a system or component and can often be produced by burning in the equipment (leaving it turned on constantly) for a few hours or days. Mechanical failures are difficult to predict but are most likely to affect devices, such as disk drives, that have moving parts.

failure rate

n. The number of failures in a specified time period. Failure rate is a means of measuring the reliability of a device, such as a hard disk. See also MTBF.

fair queuing

n. A technique used to improve quality of service that gives each session flow passing through a network device a fair share of network resources. With fair queuing, no prioritization occurs. Acronym: FQ. See also quality of service, queuing. Compare weighted fair queuing.

fair use

n. A legal doctrine describing the boundaries of legitimate use of copyrighted software or other published material.

fallout

n. Any failure of components that occurs while equipment is being burned in, especially when the test is done at the factory. See also burn in (definition 1).

Microsoft Computer Dictionary, Fifth Edition

family

n. A series of hardware or software products that have some properties in common, such as a series of personal computers from the same company, a series of CPU chips from the same manufacturer that all use the same instruction set, a set of 32-bit operating systems based on the same API (for example, Windows 95 and Windows 98), or a set of fonts that are intended to be used together, such as Times New Roman. See also central processing unit, font, instruction set, operating system.

fan1

n. The cooling mechanism built into computer cabinets, laser printers, and other such devices to prevent malfunction due to heat buildup. Fans are the main source of the continuous humming associated with computers and other hardware.

fan2

vb. To flip through a stack of printer paper to ensure that the pages are loose and will not stick together or jam the printer.

fanfold paper

n. Paper with pin-feed holes on both margins designed to be fed into the tractor-feed mechanism of a printer, page by page, in a continuous, unbroken stream. Also called: z-fold paper.

fan-in

n. The maximum number of signals that can be fed to a given electronic device, such as a logic gate, at one time without risking signal corruption. The fan-in rating of a device depends on its type and method of construction. Compare fan-out.

fan-out

n. The maximum number of electronic devices that can be fed by a given electronic device, such as a logic gate, at one time without the signal becoming too weak. The fan-out rating of a device depends on its type and method of construction. Compare fan-in.

fanzine

n. A magazine, distributed on line or by mail, that is produced by and devoted to fans of a particular group, person, or activity. See also ezine.

FAQ

n. Acronym for frequently asked questions. A document listing common questions and answers on a particular subject. FAQs are often posted on Internet newsgroups where new participants tend to ask the same questions that regular readers have answered many times.

farad

n. The unit of capacitance (the ability to hold a charge). A 1-farad capacitor holds a charge of 1 coulomb with a potential difference of 1 volt between its plates. In practical use, a farad is an extremely large amount of capacitance; capacitance is usually expressed in terms of microfarads (10–6 ) or picofarads (10–12 ). Abbreviation: F.

FARNET

n. See Federation of American Research Networks.

Fast Ethernet

n. See 100BaseX.

fast Fourier transform

Microsoft Computer Dictionary, Fifth Edition

n. A set of algorithms used to compute the discrete Fourier transform of a function, which in turn is used for solving series of equations, performing spectral analysis, and carrying out other signalprocessing and signal-generation tasks. Acronym: FFT. See also Fourier transform.

fast infrared port n. See FIR port.

fast packet

n. A standard for high-speed network technology that utilizes fast switching of fixed-length cells or packets for real-time transmission of data. Also called: Asynchronous Transfer Mode, ATM. See also packet (definition 2), packet switching.

fast packet switching

adj. Of, describing, or pertaining to high-speed packet-switching networks that perform little or no error checking. The term is often, however, restricted to high-speed networking technologies, such as ATM, that transmit fixed-length cells rather than including those, such as frame relay, that transmit variable-length packets.

fast page-mode RAM

n. See page mode RAM.

Fast SCSI

n. A form of the SCSI-2 interface that can transfer data 8 bits at a time at up to 10 megabytes per second. The Fast SCSI connector has 50 pins. Also called: Fast SCSI-2. See also SCSI, SCSI-2. Compare Fast/Wide SCSI, Wide SCSI.

Fast/Wide SCSI

n. A form of the SCSI-2 interface that can transfer data 16 bits at a time at up to 20 megabytes per second. The Fast/Wide SCSI connector has 68 pins. Also called: Fast/Wide SCSI-2. See also SCSI, SCSI-2. Compare Fast SCSI, Wide SCSI.

FAT

n. See file allocation table.

fatal error

n. An error that causes the system or application program to crash—that is, to fail abruptly with no hope of recovery.

fatal exception error

n. A Windows message signaling that an unrecoverable error, one that causes the system to halt, has occurred. Data being processed when the error occurs is usually lost, and the computer must be rebooted. See also error handling.

fat application

n. An application that can be used on both PowerPC processor–based Macintosh computers and 68K-based Macintosh computers.

fat binary

n. An application format that supports both PowerPC processor–based Macintosh computers and 68K-based Macintosh computers.

fatbits

n. 1. Originally (as FatBits), a feature of the Apple MacPaint program in which a small portion of a drawing can be enlarged and modified one pixel (FatBit) at a time. 2. A similar feature in any program that allows pixel-by-pixel modification through a zoom feature.

Microsoft Computer Dictionary, Fifth Edition

fat client

n. In a client/server architecture, a client machine that performs most or all of the processing, with little or none performed by the server. The client handles presentation and functions, and the server manages data and access to it. See also client (definition 3), client/server architecture, server (definition 2), thin server. Compare fat server, thin client.

FAT file system

n. The system used by MS-DOS to organize and manage files. The FAT (file allocation table) is a data structure that MS-DOS creates on the disk when the disk is formatted. When MS-DOS stores a file on a formatted disk, the operating system places information about the stored file in the FAT so that MS-DOS can retrieve the file later when requested. The FAT is the only file system MS-DOS can use; OS/2, Windows NT, and Windows 9x operating systems can use the FAT file system in addition to their own file systems (HPFS, NTFS, and VFAT, respectively). See also file allocation table, HPFS, NTFS, OS/2, VFAT, Windows.

father

n. See generation (definition 1).

father file

n. A file that is the last previously valid set of a changing set of data. The father file is immediately preceded by a grandfather file and immediately succeeded by its son. The pairs father and son, parent and child (or descendant), and independent and dependent are synonymous. See also generation (definition 1).

fat server

n. In a client/server architecture, a server machine that performs most of the processing, with little or none performed by the client. Applications logic and data reside on the server, and presentation services are handled by the client. See also client (definition 3), client/ server architecture, server (definition 2), thin client. Compare fat client, thin server.

fatware

n. Software that monopolizes hard disk space and power due to an overabundance of features or inefficient design. Also called: bloatware.

fault

n. 1. A physical defect, such as a loose connection, that prevents a system or device from operating as it should. 2. A programming error that can cause the software to fail. 3. As page fault, an attempt to access a page of virtual memory that is not mapped to a physical address. See also page fault.

fault resilience

n. See high availability.

fault tolerance

n. The ability of a computer or an operating system to respond to a catastrophic event or fault, such as a power outage or a hardware failure, in a way that ensures that no data is lost and any work in progress is not corrupted. This can be accomplished with a battery-backed power supply, backup hardware, provisions in the operating system, or any combination of these. In a faulttolerant network, the system has the ability either to continue the system’s operation without loss of data or to shut the system down and restart it, recovering all processing that was in progress when the fault occurred.

favorite

n. In Microsoft Internet Explorer, a user-defined shortcut to a page on the World Wide Web, analogous to a bookmark in Netscape Navigator. See also Favorites folder, hotlist. Compare bookmark (definition 2).

Microsoft Computer Dictionary, Fifth Edition

Favorites folder

n. In Microsoft Internet Explorer, a collection of shortcuts to Web sites that a user has selected for future reference. Other Web browsers refer to this collection by other names, such as bookmarks or hotlists. See also bookmark file (definition 1), Internet Explorer, URL. Compare bookmark (definition 2), hotlist.

fax

n. Short for facsimile. The transmission of text or graphics over telephone lines in digitized form. Conventional fax machines scan an original document, transmit an image of the document as a bit map, and reproduce the received image on a printer. Resolution and encoding are standardized in the CCITT Groups 1–4 recommendations. Fax images can also be sent and received by microcomputers equipped with fax hardware and software. See also CCITT Groups 1–4.

fax machine

n. Short for facsimile machine. A device that scans pages, converts the images of those pages to a digital format consistent with the international facsimile standard, and transmits the image through a telephone line. A fax machine also receives such images and prints them on paper. See also scan (definition 2).

fax modem

n. A modem that sends (and possibly receives) data encoded in a fax format (typically CCITT fax format), which a fax machine or another modem decodes and converts to an image. The image must already have been encoded on the host computer. Text and graphic documents can be converted into fax format by special software usually provided with the modem; paper documents must first be scanned in. Fax modems may be internal or external and may combine fax and conventional modem capabilities. See also fax, modem.

fax on demand

n. An automated system that makes information available for request by telephone. When a request is made, the system faxes the information to the telephone number given in the request. Acronym: FOD.

fax program

n. A computer application that allows the user to send, receive, and print fax transmissions. See also fax.

fax server

n. A computer on a network capable of sending and receiving fax transmissions to and from other computers on the network. See also fax, server (definition 1).

FCB

n. See file control block.

FCC

n. Acronym for Federal Communications Commission. The U.S. agency created by the Communications Act of 1934, which regulates interstate and international wire, radio, and other broadcast transmissions, including telephone, telegraph, and telecommunications.

F connector

n. A coaxial connector, used primarily in video applications, that requires a screw-on attachment. See the illustration.

Microsoft Computer Dictionary, Fifth Edition

F connector.

FDDI

n. Acronym for Fiber Distributed Data Interface. A standard developed by the American National Standards Institute (ANSI) for high-speed fiber-optic LANs (local area networks). FDDI provides specifications for transmission rates of 100 megabits (100 million bits) per second on networks based on the token ring standard. See also token ring network.

FDDI II

n. Acronym for Fiber Distributed Data Interface. An extension of the FDDI standard, FDDI II contains additional specifications for the real-time transmission of analog data in digitized form for high-speed fiber-optic LANs (local area networks). See also FDDI.

FDHP

n. Acronym for Full Duplex Handshaking Protocol. A protocol used by duplex modems to determine the source type of the transmission and match it. See also duplex1, handshake.

FDM

n. Acronym for Frequency Division Multiplexing. A means of loading multiple transmission signals onto separate bands of a single communications channel so that all signals can be carried simultaneously. FDM is used in analog transmissions, as on a baseband network or in communications over a telephone line. In FDM the frequency range of the channel is divided into narrower bands, each of which can carry a different transmission signal. For example, FDM might divide a voice channel with a frequency range of 1400 hertz (Hz) into four subchannels—820–990 Hz, 1230–1400 Hz, 1640–1810 Hz, and 2050–2220 Hz—with adjacent subchannels separated by a 240-Hz guard band to minimize interference.

FDMA

n. Acronym for Frequency Division Multiple Access. A method of multiplexing in which the set of frequencies assigned to cellular phone service is divided into 30 separate channels, each of which can be used by a different caller. FDMA is the technology used in the AMPS phone service, which is widespread in North America and in other countries around the world. See also AMPS. Compare TDMA.

fear, uncertainty, and doubt n. See FUD.

feasibility study

n. An evaluation of a prospective project for the purpose of determining whether or not the project should be undertaken. Feasibility studies normally consider the time, budget, and technology required for completion and are generally used in computing departments in large organizations.

feature

n. A unique, attractive, or desirable property of a program or of a computer or other hardware.

Microsoft Computer Dictionary, Fifth Edition

feature extraction

n. The selection of significant aspects of a computer image for use as guidelines in computerized pattern matching and image recognition. See also image processing.

featuritis

n. Jargon for a tendency to add new features to a program at the expense of its original compact size or elegance. Creeping featuritis describes the accretion of feature upon feature over time, eventually resulting in a large, unwieldy, generally inelegant program that is, or appears to be, a collection of ad-hoc additions. The result of featuritis is a program condition known as software bloat. Also called: creeping featuritis, creeping featurism, feeping creaturism. See also bloatware.

February 30

n. See double leap year.

Federal Communications Commission n. See FCC.

Federal Information Processing Standards

n. A system of standards, guidelines, and technical methods for information processing within the U.S. federal government. Acronym: FIPS.

Federal Internet Exchange n. See FIX.

federated database

n. A database to which scientists contribute their findings and knowledge regarding a particular field or problem. A federated database is designed for scientific collaboration on problems of such scope that they are difficult or impossible for an individual to solve. See also database.

Federation of American Research Networks

n. A nonprofit association of internetworking technology companies in the United States that serves as a national advocate for internetworking, with a primary focus on the education, research, and related communities. Acronym: FARNET. See also internetwork.

Federation on Computing in the United States

n. The U.S. representative of the International Federation of Information Processing (IFIP). Acronym: FOCUS. See also IFIP.

feed1

n. See news feed.

feed2

vb. 1. To advance paper through a printer. 2. To supply media to a recording device, as by inserting disks into a disk drive.

feedback

n. The return of a portion of system output as input to the same system. Often feedback is deliberately designed into a system, but sometimes it is unwanted. In electronics, feedback is used in monitoring, controlling, and amplifying circuitry.

feedback circuit

n. Any circuit or system that returns (feeds back) a portion of its output to its input. A common example of a feedback system, although it is not completely electronic, is a thermostatically controlled household heating system. This self-limiting or self-correcting process is an example of negative feedback, in which changes in output are fed back to the source so that the change in the output is reversed. In positive feedback, an increase in output is fed back to the source,

Microsoft Computer Dictionary, Fifth Edition

increasing the output further, which creates a snowballing effect. An example of unwanted positive feedback is the “screech” that occurs when the microphone of a public address system is brought too close to its loudspeaker.

feed scanner

n. See sheet-fed scanner.

feeping creaturism n. See featuritis.

female connector

n. A connector that has one or more receptacles for the insertion of pins. Female connector part numbers often include an F (female), an S (socket), a J (jack), or an R (receptacle). For example, a female DB-25 connector might be labeled DB-25S or DB-25F. (Note that although the letter F can denote a female connector, it does not have that meaning in F connector, which is a type of coaxial cable connector.) See the illustration. Compare male connector.

Female connector.

femto-

prefix Metric prefix meaning 10–15 (one quadrillionth).

femtosecond

n. One quadrillionth (10–15 ) of a second. Abbreviation: fs.

FEP

n. See front-end processor.

ferric oxide

n. The chemical substance Fe2O3, an oxide of iron used with a binding agent in the magnetic coating applied to disks and tapes for data storage.

ferric RAM

n. See FRAM.

ferromagnetic domain

n. See magnetic domain.

ferromagnetic material

n. A substance that can become highly magnetized. Ferrite and powdered iron are ferromagnetic materials commonly used in electronics, for example, as cores for inductors to increase their inductance, and as part of the coating on floppy and hard disks and magnetic tape.

FET

Microsoft Computer Dictionary, Fifth Edition

n. Acronym for field-effect transistor. A type of transistor in which the flow of current between the source and the drain is modulated by the electric field around the gate electrode. FETs are used as amplifiers, oscillators, and switches and are characterized by an extremely high input impedance (resistance) that makes them particularly suitable for amplification of very small signals. Types of FETs include the junction FET and the metal-oxide semiconductor FET (MOSFET). See the illustration. See also MOSFET.

FET. An N-channel junction field-effect transistor.

fetch

vb. To retrieve an instruction or an item of data from memory and store it in a register. Fetching is part of the execution cycle of a microprocessor; first an instruction or item of data must be fetched from memory and loaded into a register, after which it can be executed (if it is an instruction) or acted upon (if it is data).

fetch time

n. See instruction time.

FF

n. See form feed.

FFT

n. See fast Fourier transform.

FFTDCA

n. See Final-Form-Text DCA.

Fiber Distributed Data Interface n. See FDDI.

fiberoptic cable or fiber-optic cable

n. A form of cable used in networks that transmits signals optically, rather than electrically as do coaxial and twisted-pair cable. The light-conducting heart of a fiberoptic cable is a fine glass or plastic fiber called the core. This core is surrounded by a refractive layer called the cladding that effectively traps the light and keeps it bouncing along the central fiber. Outside both the core and the cladding is a final layer of plastic or plastic-like material called the coat, or jacket. Fiberoptic cable can transmit clean signals at speeds as high as 2 Gbps. Because it transmits light, not electricity, it is also immune to eavesdropping.

Microsoft Computer Dictionary, Fifth Edition

fiber optics

n. A technology for the transmission of light beams along optical fibers. A light beam, such as that produced in a laser, can be modulated to carry information. Because light has a higher frequency on the electromagnetic spectrum than other types of radiation, such as radio waves, a single fiber-optic channel can carry significantly more information than most other means of information transmission. Optical fibers are thin strands of glass or other transparent material, with dozens or hundreds of strands housed in a single cable. Optical fibers are essentially immune to electromagnetic interference. See also optical fiber.

fiber to the curb n. See FTTC.

fiber to the home n. See FTTH.

Fibonacci numbers

n. In mathematics, an infinite series in which each successive integer is the sum of the two integers that precede it—for example, 1, 1, 2, 3, 5, 8, 13, 21, 34, . . . . Fibonacci numbers are named for the thirteenth-century mathematician Leonardo Fibonacci of Pisa. In computing, Fibonacci numbers are used to speed binary searches by repeatedly dividing a set of data into groups in accordance with successively smaller pairs of numbers in the Fibonacci sequence. For example, a data set of 34 items would be divided into one group of 21 and another of 13. If the item being sought is in the group of 13, the group of 21 is discarded, and the group of 13 is divided into groups of 5 and 8; the search would continue until the item was located. The ratio of two successive terms in the Fibonacci sequence converges on the Golden Ratio, a “magic number” that seems to represent the proportions of an ideal rectangle. The number describes many things, from the curve of a nautilus shell to the proportions of playing cards or, intentionally, the Parthenon, in Athens, Greece. See also binary search.

fiche

n. See microfiche.

Fidonet

n. 1. A protocol for sending e-mail, newsgroup postings, and files over telephone lines. The protocol originated on the Fido BBS, initiated in 1984 by Tom Jennings, and maintaining low costs has been a factor in its subsequent development. Fidonet can exchange e-mail with the Internet. 2. The network of BBSs, private companies, NGOs (nongovernment organizations), and individuals that use the Fidonet protocol.

field

n. 1. A location in a record in which a particular type of data is stored. For example, EMPLOYEERECORD might contain fields to store Last-Name, First-Name, Address, City, State, Zip-Code, Hire-Date, Current-Salary, Title, Department, and so on. Individual fields are characterized by their maximum length and the type of data (for example, alphabetic, numeric, or financial) that can be placed in them. The facility for creating these specifications usually is contained in the data definition language (DDL). In relational database management systems, fields are called columns. 2. A space in an on-screen form where the user can enter a specific item of information.

field-effect transistor n. See FET.

field expansion

n. See date expansion.

Field Programmable Gate Array n. See FPGA.