SFDC 1021
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`Designed for
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`Microsoft'
`WindowsNr
`Windown8
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`A Use-Every-Day Computer Reference
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`The Concise Standard for Business,
`School, Libraty, and Home
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`Matter # 51198
`ow
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`Clear, up-to-date definitions
`of the terms you need to know
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`Entries cover the Internet,
`hardware, software, operating
`systems, and more
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`6 Online updates keep
`information current
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`SFDC 1021
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`PUBLISHED B Y
`Microsoft Press
`A Division of Microsoft Corporation
`One Microsoft Way
`Redmond, Washington 98052-6399
`Copyright © 1998 by Microsoft Corporation
`All rights reserved. No part of the contents of this book may be reproduced or
`transmitted in any form or by. any means without the written permission of the
`publisher.
`Library of Congress Cataloging-in-Publication Data
`Microsoft Press Computer User's Dictionary / Microsoft Corporation.
`p. cm.
`ISBN 1-57231-862-7
`1. Computers--Dictionaries. I. Microsoft Corporation.
`QA76.15.M544 1998
`004' .03--dc21 (cid:9)
`
`98-13998
`CIP
`
`Printed and bound in the United States of America.
`1 2 3 4 5 6 7 8 9 MLML 3 2 1 0 9 8
`Distributed in Canada by ITP Nelson, a division of Thomson Canada Limited.
`
`A CIP catalogue record for this book is available from the British Library.
`Microsoft Press books are available through booksellers and distributors worldwide. For
`further information about international editions, contact your local Microsoft Corporation
`office or contact Microsoft Press International directly at fax (425) 936-7329. Visit our Web site
`at mspress.microsoft.com .
`Macintosh, Power Macintosh, QuickTime, and TrueType fonts are registered trademarks of
`Apple Computer, Inc. Intel is a registered trademark of Intel Corporation. ActiveX, DirectInput,
`DirectX, Microsoft, Microsoft Press, MS-DOS, Visual Basic, Visual C++, Win32, Win32s,
`Windows, Windows NT, and XENIX are registered trademarks of Microsoft Corporation.
`Other product and company names mentioned herein may be the trademarks of their
`respective owners.
`Acquisitions Editor: Kim Fryer
`Project Editors: Teri Kieffer, Maureen Williams Zimmerman
`Manuscript Editor: Mary Renaud
`Technical Editors: John Conrow, Mary DeJong, Jim Fuchs, Roslyn Lutsch, Robert Lyon,
`Dail Magee, Jr., Kurt Meyer, Gary Nelson, Jean Ross
`
`

`
`;tandard login name used to obtain
`also anonymous FTP.
`cess a remote computer system on
`la the Internet's File Transfer Proto-
`commands for such tasks as listing
`d access rights with anonymous FTP
`om a public directory, often named
`sses the remote system with an FTP
`s or fq3 as a logon name. The pass-
`although a user can often skip
`ldress, or use the word anonymous.
`sites do not permit anonymous FTP
`
`wsgroup or mailing list that cannot
`this is accomplished by using an
`or an anonymous remailer for e-
`
`er that receives incoming messages,
`ginal sources of the messages, and
`inations. The purpose of an anony-
`the senders of the e-mail messages.
`al Standards Institute. ANSI, the
`mal Organization for Standardiza-
`For the use of programming lan-
`DL. See also ANSL SYS, ISO, SCSI.
`• for MS-DOS computers that uses
`-itrol of the console. See also ANSI,
`
`nodem to answer an incoming call
`s. Also called auto answer.
`:an receive but not originate calls.
`that can both send and receive
`n use.
`smoothing the jagged appearance
`)r resolution on a display screen.
`g pixels with intermediate shades
`alignment of pixels. Also called
`ing.
`taken to reduce reflections of
`Ti may be coated with a chemi-
`red with a polarizing filter, or
`lected into the user's eyes.
`tinimize shocks caused by the
`computer equipment or cause
`• of a floor mat, a wristband
`
`with a wire attached to the workstation, a spray, a lotion, or other special-
`purpose device. See also static', static electricity.
`antivirus program n. A computer program that scans a computer's
`memory and mass storage to identify, isolate, and eliminate viruses and that
`examines incoming files for viruses as the computer receives them.
`any key n. Any random key on a computer keyboard. Some programs
`prompt the user to "press any key" to continue. It does not matter which key
`the user presses. There is no key on the keyboard called Any.
`any-to -any connectivity n. The property of an integrated computer net-
`work environment where it is possible to share data across multiple proto-
`cols, host types, and network topologies.
`APA n. See all points addressable.
`API n. See application programming interface.
`app n. See application.
`append vb. To place or insert as an attachment by adding data to the end
`of a file or database or by extending a character string. See also character
`string, file. Compare truncate.
`Apple Desktop Bus n. A serial communications pathway built into Apple
`Macintosh and Apple IIGS computers. Typically a flexible cord, it enables
`low-speed input devices, such as a keyboard or mouse, to communicate
`with the computer. The bus functions like a simple local area network that
`can connect up to 16 devices to the computer. Although there are only two
`external ports, more than two devices can be daisy-chained together. Acro-
`nym: ADB. See also bus, daisy chain, device driver, input/output port, serial
`communications.
`Apple key n. A key on Apple keyboards labeled with an outline of the
`Apple logo. On the Apple Extended Keyboard, this key is the same as the
`Command key, which functions similarly to the Control key on IBM and
`compatible keyboards. It is generally used in conjunction with a character
`key as a shortcut to making menu selections or starting a macro.
`Apple Macintosh n. See Macintosh.
`AppleShare n. File server software that works with the Mac OS and allows
`one Macintosh computer to share files with another on the same network.
`See also file server, Mac OS.
`applet n. A small piece of code that can be transported over the Internet
`and executed on the recipient's machine. The term is used especially to
`refer to such programs embedded as objects in HTML documents on the
`World Wide Web.
`AppleTalk n. An inexpensive local area network developed by Apple that
`can be used by Apple and non-Apple computers to communicate and share
`resources such as printers and file servers. Non-Apple computers must be
`equipped with AppleTalk hardware and suitable software.
`application n. A program designed to assist in the performance of a spe-
`cific task, such as word processing, accounting, or inventory management.
`Compare utility.
`
`

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`dual-scan displays are more economical in terms of power consumption hut
`have less clarity and a smaller viewing angle. See also passive-matrix display,
`refresh rate.
`dual-sided disk drive n. A disk drive that can read or write information to
`both the top and bottom sides of a double-sided disk. Dual-sided disk drivr<,
`have two read/write heads, one for each disk surface.
`dumb quotes n. Quotation marks that have the same appearance (usu I k
`upright, like the apostrophe ' and the quotation marks " on a typewl lktt
`whether they stand before or after the material being quoted. Coin/noo
`smart quotes.
`dumb terminal n. A terminal that does not contain an internal micro' nt
`.cessor. Dumb terminals are typically capable of displaying only charai IW4
`and numbers and responding to •simple control codes. See also terimn a I
`Compare smart terminal.
`dummy n. A placeholder, usually a character, a record, or a variablc, t h,l,
`is used to reserve space until the intended item is available.
`duplex' adj. Capable of carrying information in both directions ovi<t •
`communications channel. A system is full-duplex if it can carry inform.o
`in both directions at once; it is half-duplex if it can carry information in oil.
`one direction at a time.
`duplex2 n. 1. Simultaneous communications, in both directions, I <et
`the sender and receiver. Also called duplex transmission, full-duplcit II al ,
`mission. See also half-duplex transmission. 2. Photographic paper on
`an image can be printed on both sides.
`duplex channel n. A communications link that allows for dupk's t to
`way) transmission.
`duplex printer n. A printer capable of printing on both sides of ilk'
`duplex system n. A system of two computers, one of which is act IS v1 . 14
`the other remains on standby, ready to take over processing if the
`machine malfunctions.
`duplex transmission n. See duplex' (definition 1).
`duplicate key n. A value assigned to an indexed field in one Iv< <it d
`database that duplicates a value assigned to the same field in anot lei I
`in the database. For example, a key composed of ZIP-CODE would
`duplicate values if the file contained a number of addresses from 1 , t
`Zip code. A field in which duplicate values are permitted cannot ' ,4
`primary key because the primary key must be unique. See also ficlii I 1
`tion 1), key (definition 2), primary key.
`DVD n. See digital video disc.
`DVD-E n. See digital video disc–erasable. •
`DVD-R n. See digital video disc–recordable.
`DVD-ROM n. See digital video disc–ROM.
`Dvorak keyboard n. A keyboard layout developed as an alterniti
`popular QWERTY keyboard. The Dvorak keyboard was designi'd
`
`tk (cid:9)
`
`n
`
`dynamic random access memory
`
`typing by placing the characters on the keyboard for easiest access to the
`most frequently typed letters. See also ergonomic keyboard, keyboard. Com-
`pare QWERTY keyboard.
`DXF n. Short for drawing interchange format. A computer-aided design file
`format originally developed for use with the AutoCAD program to facilitate
`transfer of graphics files between applications.
`dye-diffusion printer n. See continuous-tone printer.
`dye-sublimation printer n. See continuous-tone printer.
`dynalink n. Short for dynamic link. See dynamic-link library.
`dynamic adj. Occurring immediately and concurrently. For both hardware
`and software, the term describes some action or event that occurs when and
`as needed. In dynamic memory management, for example, a program is
`ithle to negotiate with the operating system when it needs more memory.
`Dynamic Data Exchange n. See DDE.
`dynamic HTML n. A technology designed to add interactivity and graphi-
`cal interest to Web pages by allowing those pages to change and update
`I Iternselves dynamically—that is, in response to user actions, without the
`to -d for repeated downloads from a server. Dynamic HTML enables client-
`vtkli. scripts (programs that affect elements on a Web page) produced with
`Itinguages such as VBScript and JavaScript to control and manipulate ele-
`ments such as fonts and graphics by means of HTML tags. For the user,
`dynamic HTML produces the type of interactivity and relatively rapid down-
`Iliad times associated with multimedia CD-ROM products. See also HTML.
`dynamic keys n. An encryption technique in which messages are en-
`ty pled differently for each transmission based on different keys so that if a
`<I is captured and decrypted, it will never be useful again. See also encryp-
`I, key (definition 3).
`iiittnic-link library n. A feature of the Windows family of operating sys-
`and OS/2 that allows executable routines to be stored separately as
`with DLL extensions and to be loaded only when needed by a program.
`
`i<<nytn: DLL.
`
`page n. An HTML document that contains animated GIFs, Java
`Apt tlot,i, or ActiveX controls. See also ActiveX controls, animated GIF, HTML,
`
`n. A form of semiconductor RAM. Dynamic RAMs store in-
`million in integrated circuits containing capacitors. Because capacitors
`their charge over time, dynamic RAM boards must include logic to re-
`troaarge) the RAM chips continuously. While a dynamic RAM is being
`iod, it cannot be read by the processor. Despite being slower, dy-
`It AMs are more common than RAMs because their circuitry is simpler
`t<i ‘i use they can hold up to four times as much data. Acronym: DRAM.
`IlAM, Compare static RAM.
`tilt: random access memory n. See dynamic RAM,
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`laptop
`
`laptop n. A small, portable personal computer that runs on either batteries
`or AC power, designed for use during travel. Laptops have flat LCD or
`plasma screens and small keyboards. Most can run the same software as
`their desktop counterparts and can accept similar peripherals, such as sound
`cards, internal or external modems, and floppy disks and CD-ROM drives.
`Some laptops are designed to be plugged into a docking station, effectively
`making them desktop computers. Most have connectors for plugging in ex-
`ternal keyboards and full-size monitors. Although ultralight portable com-
`puters are generally known as notebook computers, these machines are also
`commonly referred to as laptops. See also portable computer. Compare
`subnotebook computer.
`laser or LASER n. Acronym for light amplification by stimulated emission
`of radiation. A device that uses certain quantum effects to produce coherent
`light, which travels with greater efficiency than noncoherent light because
`the beam diverges only slightly as•it travels. Lasers are used in computer
`technology to transmit data through fiber-optic cables, to read and write
`data on CD-ROMs, and to place an image on a photosensitive drum in laser
`printers.
`laser engine n. See printer engine.
`laser printer n. An electrophotographic printer based on the technology
`used by photocopiers. A focused laser beam and a rotating mirror are used
`to draw an image of the page on a photosensitive drum. This image is con-
`verted to an electrostatic charge, which attracts and holds toner. Paper is
`rolled against the drum, and the toner is pulled away from the drum and
`onto the paper. Heat then fuses the toner to the paper. This process, which
`results in crisp, clear images, makes laser printers the standard for high-
`quality printing. The only serious drawback of a laser printer is that it offers
`less paper-handling flexibility than dot-matrix printers. Both multipart forms
`and wide-carriage printing, for example, are better handled by line printers
`or dot-matrix printers. See also electrophotographic printers, nonimpact
`printer, page printer. Compare dot-matrix printer, LCD printer, LED printer.
`laser storage n. The use of optical read/write technology with metallic
`discs for information storage. See also compact disc.
`last in, first out n. A method of processing a queue in which items are
`removed in inverse order relative to the order in which they were added-
`that is, the last in is the first out. Acronym: LIFO. Compare first in, first out.
`latency n. The time required for a signal to travel from one point on a
`network to another.
`launch vb. To activate a program (especially on the Macintosh) from the
`operating system's user interface.
`layer n. 1. The protocol or protocols operating at a particular level within a
`protocol suite, such as IP within the TCP/1P suite. Each layer is responsible
`for providing specific services or functions for computers exchanging infor-
`mation over a communications network (such as the layers outlined in the
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`LED printer
`
`ISO/OSI model), and information is passed from one layer to the next. Al-
`though different suites have varying numbers of levels, generally the highest
`layer deals with software interactions at the application level, and the lowest
`governs hardware-level connections between different computers. See also
`ISO/OSI model, protocol stack, TCP/IP. 2. In communications and distrib-
`uted processing, a set of rules and standards that handles a particular class
`of events.
`layering n. In computer graphics, the grouping of logically related ele-
`ments in a drawing. Layering enables a user to view, and work on indepen-
`dently, portions of a graphic instead of the entire drawing.
`layout n. 1. The overall plan or design of a document system. See also page
`layout. 2. In computer design, the arrangement of circuits and other compo-
`nents of the system.
`LCD n. See liquid crystal display.
`LCD printer n. Short for liquid crystal display printer. An electrophoto-
`graphic printer similar to a laser printer and often incorrectly labeled as one.
`LCD printers use a bright light source, typically a halogen lamp. Also called
`liquid crystal shutter printer. See also electrophotographic printers, non-
`impact printer, page printer. Compare laser printer, LED printer.
`LCD projector n. Short for liquid crystal display projector. A device that
`casts an image of a computer's video output from a liquid crystal display
`onto a screen. See also liquid crystal display.
`lead n. See leading.
`leader n. A row of dots, hyphens, or other such characters used to lead the
`eye across a printed page to related information.
`leading n. The vertical space, expressed in points, between lines of type,
`measured from the baseline (bottom) of one line to the baseline of the next.
`Also called lead, line spacing. See also point (definition 1).
`leading zero n. A zero that precedes the most significant (leftmost) digit of
`a number. One or more leading zeros may be used as fill characters in a
`field containing numeric input. Leading zeros have no significance in the
`value of a number.
`lead ion battery n. An energy storage device based on the conversion of
`chemical to electrical energy as ions flow from one terminal to another
`through an acid medium in which lead and copper are suspended. This type
`of battery is used in laptop and notebook computers.
`leaf n. Any node (location) in a tree structure that is at the farthest distance
`from the root (primary node), no matter which path is followed. Thus, in
`any tree, a leaf is a node at the end of a branch—one that has no descen-
`dants. See also root, tree.
`leased line n. See dedicated line (definition 1).
`LED n. See light-emitting diode.
`LED printer n. Short for light-emitting diode printer. An electrophoto-
`graphic printer similar to LCD and laser printers but using a different light
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