A Gathering Place: Microsoft Glossary of Terms 5

~B~

Backbone-through-Bit Image

A/B Switch box ~ America On-line AMI BIOS ~ Arithmetic Operation ARP ~ AVI Backbone ~ Bit Image Bit Map ~ Boot Disk Boot Drive ~ Bytes Per Inch C++ ~ Carrier Frequency carrier system ~ certification CGI ~ Chooser extension cipher ~ Clipper Chip clock ~ color color bits ~ communications satellite communications server ~ computer security CON ~ copy copy program ~ cycle time daemon ~ defragmentation demand paging ~ digitize DikuMUD ~ disk disk buffer ~ Document Style Semantics and Specification Language document window ~ dynamic Web page Easter egg ~ erase erase head ~ ezine F2F ~ finger2 firewall ~ font suitcase footer ~ FYI Game Control Adapter ~ GUI HAL ~ hot key1 hot key2 ~ Hz i486DX ~ internal modem internet ~ ISO 9660 ISO/OSI model ~ just-in-time K1 ~ knowledge base L1 cache ~ LU luggable computer ~ LZW compression MAC ~ MILNET mime ~ msec MTBF ~ MYOB named anchor ~ network drive Network File System ~ number crunching object ~ overwrite mode P5 ~ PC/XT keyboard PDA ~ pipeline processing piracy ~ preventive maintenance preview ~ pwd quasi-language ~ QWERTY keyboard R&D ~ registration marks Registry ~ RFI RF shielding ~ run-time library SAA ~ server error server push-pull ~ soft return software ~ style sheet stylus ~ System T1 ~ ToggleKeys token ~ typography UART ~ uupc V.120 ~ view2 viewer ~ VxD w3 ~ WinG WINS ~ WWW X.25 ~ X Windows Yahoo! ~ yotta- Z39.50 standard ~ Zulu time

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backbone

n. 1. A network of communication transmission that carries major traffic between smaller networks. The backbones of the Internet, including communications carriers such as Sprint and MCI, can span thousands of miles using microwave relays and dedicated lines.

2. The smaller networks (compared with the entire Internet) that perform the bulk of the packet switching of Internet communication. Today these smaller networks still consist of the networks that were originally developed to make up the Internet--the computer networks of the educational and research institutions of the United States--especially NSFnet, the computer network of the National Science Foundation in Oak Ridge, Tennessee. See also NSFnet, packet switching. 3. The wires that carry major communications traffic within a network. In a local area network, a backbone may be a bus. Also called collapsed backbone.

backbone cabal

n. On the Internet, a term for the group of network administrators responsible for naming the hierarchy of Usenet newsgroups and devising the procedures for creating new newsgroups. The backbone cabal no longer exists.

back door

n. A means of gaining access to a program or system by bypassing its security controls. Programmers often build back doors into systems under development so that they can fixs bugs. If the back door becomes known to anyone other than the programmer, or if it is not removed before the software is released, it becomes a security risk. Also called trapdoor.

back end

n. 1. In a client/server application, the part of the program that runs on the server. See also client/server architecture. Compare front end. 2. The part of a compiler that transforms source code (human-readable program statements) into object code (machine-readable code). See also compiler (definition 2), object code, source code.

background1

adj. In the context of processes or tasks that are part of an operating system or program, operating without interaction with the user while the user is working on another task. Background processes or tasks are assigned a lower priority in the microprocessor's allotment of time than foreground tasks and generally remain invisible to the user unless the user requests an update or brings the task to the foreground. Generally, only multitasking operating systems are able to support background processing. However, some operating systems that do not support multitasking may be able to perform one or more types of background tasks. For example, in the Apple Macintosh operating system running with multitasking turned off, the Background Printing option can be used to print documents while the user is doing other work. See also multitasking. Compare foreground1.

background2

n. 1. The color against which characters and graphics are displayed, such as a white background for black characters. Compare foreground2 (definition 1). 2. The colors, textures, patterns, and pictures that comprise the surface of the desktop, upon which icons, buttons, menu bars, and toolbars are situated. See also wallpaper (definition 1). 3. The colors, textures, patterns, and pictures that comprise the surface of a Web page, upon which text, icons, graphics, buttons, and other items are situated. See also wallpaper (definition 2). 4. The condition of an open but currently inactive window in a windowing environment. See also inactive window. Compare foreground2 (definition 2).

background noise

n. The noise inherent in a line or circuit, independent of the presence of a signal. See also noise.

background printing

n. The process of sending a document to a printer at the same time that the computer is performing one or more tasks.

background processing

n. The execution of certain operations by the operating system or a program during momentary lulls in the primary (foreground) task. An example of a background process is a word processor program printing a document during the time between the user's keystrokes. See also background1.

back-lit display

n. An LCD display that uses a light source behind the screen to enhance image sharpness and readability, especially in environments that are brightly lit.

backslash

n. The character (\) used to separate directory names in MS-DOS path specifications. When used as a leading character, it means that the path specification begins from the topmost level for that disk drive. See also path.

Backspace key

n. 1. A key that, on IBM and compatible keyboards, moves the cursor to the left, one character at a time, usually erasing each character as it moves. 2. On Macintosh keyboards, a key (called the Delete key on some Macintosh keyboards) that erases currently selected text or, if no text is selected, erases the character to the left of the insertion point (cursor).

backup

n. A duplicate copy of a program, a disk, or data, made either for archiving purposes or for safeguarding valuable files from loss should the active copy be damaged or destroyed. A backup is an "insurance" copy. Some application programs automatically make backup copies of data files, maintaining both the current version and the preceding version on disk. Also called backup copy, backup file.

backup and restore

n. The process of maintaining backup files and putting them back onto the source medium if necessary.

bad sector

n. A disk sector that cannot be used for data storage, usually because of media damage or imperfections. Finding, marking, and avoiding bad sectors on a disk is one of the many tasks performed by a computer's operating system. A disk-formatting utility can also find and mark the bad sectors on a disk.

balloon help

n. In the Mac OS 7.x, an on-screen help feature in the form of a cartoon dialog balloon. After activating this feature by clicking on the ballon icon on the toolbar, the user can position the cursor over an icon or other item, and a dialog balloon will appear that describes the function of the item.

band

n. 1. In printing graphics, a rectangular portion of a graphic sent by the computer to a printer. The technique of dividing a graphic into bands prevents a printer from having to reconstruct an entire image in memory before printing it. 2. In communications, a contiguous range of frequencies used for a particular purpose, such as radio or television broadcasts.

bandwidth

n. 1. The difference between the highest and lowest frequencies that an analog communications system can pass. For example, a telephone accommodates a bandwidth of 3,000 Hz: the difference between the lowest (300 Hz) and highest (3,300 Hz) frequencies it can carry. 2. The data transfer capacity of a digital communications system.

bank

n. 1. Any group of similar electrical devices connected together for use as a single device. For example, transistors may be connected in a row/column array inside a chip to form memory, or several memory chips may be connected together to form a memory module such as a SIMM. See also SIMM. 2. A section of memory, usually of a size convenient for a CPU to address. For example, an 8-bit processor can address 65,536 bytes of memory; therefore, a 64-kilobyte (64-KB) memory bank is the largest that the processor can address at once. To address another 64-KB bank of memory requires circuitry that fools the CPU into looking at a separate block of memory. See also bank switching, page (definition 2).

bank switching

n. A method of expanding a computer's available random access memory (RAM) by switching between banks of RAM chips that share a range of memory addresses, which is set aside before switching begins. Only one bank is directly accessible at a time; when a bank is not active, it retains whatever is stored in it. Before another bank can be used, the operating system, driver, or program must explicitly issue a command to the hardware to make the switch. Because switching between banks takes time, memory-intensive operations take longer with bank-switched memory than with main memory. Bank-switched memory typically takes the form of an expansion card that plugs into a slot on the motherboard.

banner

n. A section of a Web page containing an advertisement that is usually an inch or less tall and spans the width of the Web page. The banner contains a link to the advertiser's own Web site. See also Web page, Web site.

banner page

n. 1. The title page that may be added to printouts by most print spoolers. Such a page typically incorporates account ID information, job length, and print spooler information, and is used primarily to separate one print job from another. See also print spooler. 2. In software, an initial screen used to identify a product and credit its producers.

bar chart

n. A type of graphic in which data items are shown as rectangular bars. The bars may be displayed either vertically or horizontally and may be distinguished from one another by color or by some type of shading or pattern. Positive and negative values may be shown in relation to a zero baseline. Two types of bar charts are common: a standard bar chart, in which each value is represented by a separate bar, and a stacked bar chart, in which several data points are "stacked" to produce a single bar. Also called bar graph.

bar code

n. The special identification code printed as a set of vertical bars of differing widths on books, grocery products, and other merchandise. Used for rapid, error-free input in such facilities as libraries, hospitals, and grocery stores, bar codes represent binary information that can be read by an optical scanner. The coding can include numbers, letters, or a combination of the two; some codes include built-in error checking and can be read in either direction.

bare bones2

n. 1. An application that provides only the most basic functions necessary to perform a given task. 2. A computer consisting only of motherboard (equipped with CPU and RAM), cabinet, power supply, floppy disk drive, and keyboard, to which the user must add hard disk, video adapter, monitor, and any other peripherals. See also motherboard, peripheral.

base address

n. The part of a two-part memory address that remains constant and provides a reference point from which the location of a byte of data can be calculated. A base address is accompanied by an offset value that is added to the base to determine the exact location (the absolute address) of the information. The concept is similar to a street address system. For example, "2010 Main Street" consists of a base (the 2000 block of Main Street) plus an offset (10 from the beginning of the block). Base addresses are known as segment addresses in IBM PCs and compatibles; data in these computers is identified by its position as a relative offset from the start of the segment. See also absolute address, offset, relative address, segment.

baseband

adj. Of or relating to communications systems in which the medium of transmission (such as a wire or fiber-optic cable) carries a single message at a time in digital form. Baseband communication is found in local area networks such as Ethernet and Token Ring. See also Ethernet, fiber optics, Token Ring network. Compare broadband.

baseband network

n. A type of local area network in which messages travel in digital form on a single transmission channel between machines connected by coaxial cable or twisted-pair wiring. Machines on a baseband network transmit only when the channel is not busy, although a technique called time-division multiplexing can enable channel sharing. Each message on a baseband network travels as a packet that contains information about the source and destination machines as well as message data. Baseband networks operate over short distances at speeds ranging from about 50 kilobits per second (50 Kbps) to 16 megabits per second (16 Mbps). Receiving, verifying, and converting a message, however, add considerably to the actual time, reducing throughput. The maximum recommended distance for such a network is about 2 miles, or considerably less if the network is heavily used. See also coaxial cable, multiplexing, packet, throughput, time-division multiplexing, twisted-pair cable. Compare broadband network.

baseline

n. In the printing and display of characters on the screen, an imaginary horizontal line with which the base of each character, excluding descenders, is aligned. See also ascender, descender, font.

Basic

or BASIC n. Acronym for Beginner's All-purpose Symbolic Instruction Code, a high-level programming language developed in the mid-1960s by John Kemeny and Thomas Kurtz at Dartmouth College. It is widely considered one of the easiest programming languages to learn. See also True Basic, Visual Basic.

batch

n. A group of documents or data records that are processed as a unit. See also batch job, batch processing.

batch file

n. An ASCII text file containing a sequence of operating-system commands, possibly including parameters and operators supported by the batch command language. When the user types a batch filename at the command prompt, the commands are processed sequentially. Also called batch program. See also AUTOEXEC.BAT, .bat.

batch job

n. A program or set of commands that runs without user interaction. See also batch processing.

batch processing

n. 1. Execution of a batch file. See also batch file. 2. The practice of acquiring programs and data sets from users, running them one or a few at a time, and then providing the results to the users. 3. The practice of storing transactions for a period of time before they are posted to a master file, typically in a separate operation undertaken at night. Compare transaction processing.

batch program

n. A program that executes without interacting with the user. See also batch file. Compare interactive program.

battery

n. Two or more cells in a container that produces an electrical current when two electrodes within the container touch an electrolyte. In personal computers, batteries are used as an auxiliary source of power when the main power is shut off, as a power source for laptop and notebook computers (rechargeable batteries, such as nickel cadmium, nickel metal hydride, and lithium ion, are used), and as a method to keep the internal clock and the circuitry responsible for the part of RAM that stores important system information always powered up. See also lead ion battery, lithium ion battery, nickel cadmium battery, nickel metal hydride battery, RAM.

battery backup

n. 1. A battery-operated power supply used as an auxiliary source of electricity in the event of a power failure. 2. Any use of a battery to keep a circuit running when the main power is shut off, such as powering a computer's clock/calendar and the special RAM that stores important system information between sessions. See also UPS.

baud

n. One signal change per second, a measure of data transmission speed. Named after the French engineer and telegrapher Jean-Maurice-Emile Baudot and originally used to measure the transmission speed of telegraph equipment, the term now most commonly refers to the data transmission speed of a modem. See also baud rate.

baud rate

n. The speed at which a modem can transmit data. The baud rate is the number of events, or signal changes, that occur in one second--not the number of bits per second (bps) transmitted. In high-speed digital communications, one event can actually encode more than one bit, and modems are more accurately described in terms of bits per second than baud rate. For example, a so-called 9,600-baud modem actually operates at 2,400 baud but transmits 9,600 bits per second by encoding 4 bits per event (2,400 + 4 = 9,600) and thus is a 9,600-bps modem. Compare bit rate, transfer rate.

bay

n. A shelf or opening used for the installation of electronic equipment--for example, the space reserved for additional disk drives, CD-ROM drives, or other equipment in the cabinets of microcomputers. See also drive bay.

BBS

n. 1. Acronym for bulletin board system. A computer system equipped with one or more modems or other means of network access that serves as an information and message-passing center for remote users. Often BBSs are focused on special interests, such as science fiction, movies, Windows software, or Macintosh systems, and can have free or fee-based access, or a combination. Users dial into a BBS with their modems and post messages to other BBS users in special areas devoted to a particular topic, in a manner reminiscent of the posting of notes on a cork bulletin board. Many BBSs also allow users to chat online with other users, send e-mail, download and upload files that include freeware and shareware software, and access the Internet. Many software and hardware companies run proprietary BBSs for customers that include sales information, technical support, and software upgrades and patches. 2. Acronym for be back soon. A shorthand expression often seen in Internet discussion groups by a participant leaving the group who wishes to bid a temporary farewell to the rest of the group.

Bcc

n. Acronym for blind courtesy copy. A feature of e-mail programs that allows a user to send a copy of an e-mail message to a recipient without notifying other recipients that this was done. Generally, the recipient's address is entered into a field called "bcc:" in the mail header. Also called blind carbon copy. See also e-mail, header (definition 1). Compare cc.

bearer channel

n. One of the 64-Kbps communications channels on an ISDN circuit. A BRI (Basic Rate Interface) ISDN line has 2 bearer channels and 1 data channel. A PRI (Primary Rate Interface) ISDN line has 23 bearer channels (in North America) or 30 bearer channels (in Europe) and 1 data channel. See also BRI, channel (definition 2), ISDN.

bells and whistles

n. Attractive features added to hardware or software beyond basic functionality, comparable to accessories, such as electric door locks and air conditioning, added to an automobile. Products, especially computer systems, without such adornments are sometimes called "plain vanilla."

benchmark1

n. A test used to measure hardware or software performance. Benchmarks for hardware use programs that test the capabilities of the equipment--for example, the speed at which a CPU can execute instructions or handle floating-point numbers. Benchmarks for software determine the efficiency, accuracy, or speed of a program in performing a particular task, such as recalculating data in a spreadsheet. The same data is used with each program tested, so the resulting scores can be compared to see which programs perform well and in what areas. The design of fair benchmarks is something of an art, because various combinations of hardware and software can exhibit widely variable performance under different conditions. Often, after a benchmark has become a standard, developers try to optimize a product to run that benchmark faster than similar products run it in order to enhance sales. See also sieve of Eratosthenes.

benchmark2

vb. To measure the performance of hardware or software.

benign virus

n. A program that exhibits properties of a virus, such as self-replication, but does not otherwise do harm to the computer systems that it infects.

best of breed

adj. A term used to describe a product that is the best in a particular category of products.

beta1

adj. Of or relating to software or hardware that is a beta. See also beta2. Compare alpha1.

beta2

n. A new software or hardware product, or one that is being updated, that is ready to be released to users for beta testing. See also beta test.

beta site

n. An individual or an organization that tests software before it is released to the public. The company producing the software usually selects these beta sites from a pool of established customers or volunteers. Most beta sites perform this service free of charge, often to get a first look at the software and to receive free copies of the software once it is released to the public.

beta test

n. A test of software that is still under development, accomplished by having people actually use the software. In a beta test, a software product is sent to selected potential customers and influential end users (known as beta sites), who test its functionality and report any operational or utilization errors (bugs) found. The beta test is usually one of the last steps a software developer takes before releasing the product to market; however, if the beta sites indicate that the software has operational difficulties or an extraordinary number of bugs, the developer may conduct more beta tests before the software is released to customers.

B_zier curve

n. A curve that is calculated mathematically to connect separate points into smooth, free-form curves and surfaces of the type needed for illustration programs and CAD models. B_zier curves need only a few points to define a large number of shapes-- hence their usefulness over other mathematical methods for approximating a given shape. See also CAD.

bias

n. 1. A uniform or systematic deviation from a point of reference. 2. In mathematics, an indication of the amount by which the average of a group of values deviates from a reference value. 3. In electronics, a voltage applied to a transistor or other electronic device to establish a reference level for its operation. 4. In communications, a type of distortion in the length of transmitted bits, caused by a lag that occurs as voltage builds up or falls off each time the signal changes from 0 to 1 or vice versa.

bidirectional

adj. Operating in two directions. A bidirectional printer can print from left to right and from right to left; a bidirectional bus can transfer signals in both directions between two devices.

bidirectional parallel port

n. An interface that supports two-way parallel communication between a device and a computer.

bidirectional printing

n. The ability of an impact or ink-jet printer to print from left to right and from right to left. Bidirectional printing improves speed substantially because no time is wasted returning the print head to the beginning of the next line, but it may lower print quality.

Big Blue

n. The International Business Machines (IBM) Corporation. This nickname comes from the corporate color used on IBM's early mainframes and still used in the company logo.

binary1

adj. Having two components, alternatives, or outcomes. The binary number system has 2 as its base, so values are expressed as combinations of two digits, 0 and 1. These two digits can represent the logical values true and false as well as numerals, and they can be represented in an electronic device by the two states on and off, recognized as two voltage levels. Therefore, the binary number system is at the heart of digital computing. Although ideal for computers, binary numbers are usually difficult for people to interpret because they are repetitive strings of 1s and 0s. To ease translation, programmers and others who habitually work with the computer's internal processing abilities use hexadecimal (base-16) or octal (base-8) numbers. Equivalents and conversion tables for binary, decimal, hexadecimal, and octal are in Appendix E. See also base, binary-coded decimal, binary number, bit, Boolean algebra, byte, cyclic binary code, digital computer, dyadic, logic circuit. Compare ASCII, decimal, hexadecimal, octal.

binary2

n. In an FTP client program, the command that instructs the FTP server to send or receive files as binary data. See also FTP client, FTP server. Compare ASCII.

binary digit

n. Either of the two digits in the binary number system, 0 and 1. See also bit.

binary file

n. A file consisting of a sequence of 8-bit data or executable code, as distinguished from files consisting of human-readable ASCII text. Binary files are usually in a form readable only by a program, often compressed or structured in a way that is easy for a particular program to read. Compare ASCII file.

binary file transfer

n. Transfer of a file containing arbitrary bytes or words, as opposed to a text file containing only printable characters (for example, ASCII characters with codes 10, 13, and 32-126). On modern operating systems a text file is simply a binary file that happens to contain only printable characters, but some older systems distinguish the two file types, requiring programs to handle them differently. Acronym: BFT.

binary format

n. Any format that structures data in 8-bit form. Binary format is generally used to represent object code (program instructions translated into a machine-readable form) or data in a transmission stream. See also binary file.

binary notation

n. Representation of numbers using the binary digits, 0 and 1. Compare floating- point notation.

binary number

n. A number expressed in binary form. Because binary numbers are based on powers of 2, they can be interpreted as follows: See also binary1. k:\compdict\database\8780.doc

binary search

n. A type of search algorithm that seeks an item, with a known name, in an ordered list by first comparing the sought item to the item at the middle of the list's order. The search then divides the list in two, determines in which half of the order the item should be, and repeats this process until the sought item is found. Also called binary chop, dichotomizing search. See also search algorithm. Compare hash search, linear search.

binary transfer

n. The preferred mode of electronic exchange for executable files, application data files, and encrypted files. Compare ASCII transfer.

binary tree

n. In programming, a specific type of tree data structure in which each node has at most two subtrees, one left and one right. Binary trees are often used for sorting information; each node of the binary search tree contains a key, with values less than that key added to one subtree and values greater than that key added to the other. See also binary search, tree.

bind

vb. To associate two pieces of information with one another. The term is most often used with reference to associating a symbol (such as the name of a variable) with some descriptive information (such as a memory address, a data type, or an actual value). See also binding time, dynamic binding, static binding.

BinHex1

n. 1. A code for converting binary data files into ASCII text so they can be transmitted via e-mail to another computer or in a newsgroup post. This method can be used when standard ASCII characters are needed for transmission, as they are on the Internet. BinHex is used most frequently by Mac users. See also MIME. 2. An Apple Macintosh program for converting binary data files into ASCII text and vice versa using the BinHex code. Compare uudecode1, uuencode1.

BinHex2

vb. To convert a binary file into printable 7-bit ASCII text or to convert the resulting ASCII text file back to binary format using the BinHex program. Compare uudecode, uuencode2.

BIOS

n. Acronym for basic input/output system. On PC-compatible computers, the set of essential software routines that test hardware at startup, start the operating system, and support the transfer of data among hardware devices. The BIOS is stored in read- only memory (ROM) so that it can be executed when the computer is turned on. Although critical to performance, the BIOS is usually invisible to computer users. See also AMI BIOS, CMOS setup, Phoenix BIOS, ROM BIOS. Compare Toolbox.

bit

n. Short for binary digit. The smallest unit of information handled by a computer. One bit expresses a 1 or a 0 in a binary numeral, or a true or false logical condition, and is represented physically by an element such as a high or low voltage at one point in a circuit or a small spot on a disk magnetized one way or the other. A single bit conveys little information a human would consider meaningful. A group of 8 bits, however, makes up a byte, which can be used to represent many types of information, such as a letter of the alphabet, a decimal digit, or other character. See also ASCII, binary, byte.

bit bucket

n. An imaginary location into which data can be discarded. A bit bucket is a null input/output device from which no data is read and to which data can be written without effect. The NUL device recognized by MS-DOS is a bit bucket. A directory listing, for example, simply disappears when sent to NUL.

bit flipping

n. A process of inverting bits--changing 1s to 0s and vice versa. For example, in a graphics program, to invert a black-and-white bitmapped image (to change black to white and vice versa), the program could simply flip the bits that compose the bit map.

bit image

n. A sequential collection of bits that represents in memory an image to be displayed on the screen, particularly in systems having a graphical user interface. Each bit in a bit image corresponds to one pixel (dot) on the screen. The screen itself, for example, represents a single bit image; similarly, the dot patterns for all the characters in a font represent a bit image of the font. In a black-and-white display each pixel is either white or black, so it can be represented by a single bit. The "pattern" of 0s and 1s in the bit image then determines the pattern of white and black dots forming an image on the screen. In a color display the corresponding description of on-screen bits is called a pixel image because more than one bit is needed to represent each pixel. See also bit map, pixel image.

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