MICROSOFT Computer Dictionary, Fifth Edition

Microsoft Computer Dictionary, Fifth Edition

sensor

n. A device that detects or measures something by converting nonelectrical energy to electrical energy. A photocell, for example, detects or measures light by converting it to electrical energy. See also transducer.

sensor glove

n. A hand-worn computer input device for virtual-reality environments. The glove translates finger movements by the user to commands for manipulating objects in the environment. Also called: data glove. See also virtual reality.

SEPP

n. Acronym for Software Engineering for Parallel Processing. A project of nine European universities and research institutions to develop tools for the development of parallel application programs for distributed memory multiprocessors.

sequence

n. An ordered arrangement, as in a set of numbers, such as the Fibonacci sequence. See also Fibonacci numbers.

sequence check

n. A process that verifies that data or records conform to a particular order. Compare completeness check, consistency check, duplication check.

Sequenced Packet Exchange n. See SPX (definition 1).

sequential access

n. A method of storing or retrieving information that requires the program to start reading at the beginning and continue until it finds the desired data. Sequential access is best used for files in which each piece of information is related to the information that comes before it, such as mailing list files and word processing documents. Also called: serial access. See also indexed sequential access method. Compare random access.

sequential algorithm

n. An algorithm in which each step must occur in a particular order. See also algorithm. Compare parallel algorithm.

sequential execution

n. The act of executing routines or programs in a linear sequence. Compare concurrent execution.

sequential logic element

n. A logic circuit element that has at least one input and one output and in which the output signal depends on the present and past states of the input signal or signals.

sequential processing

n. 1. The processing of items of information in the order in which they are stored or input. 2. The execution of one instruction, routine, or task followed by the execution of the next in line. Compare multiprocessing, parallel processing, pipelining (definition 1).

sequential search n. See linear search.

serial

Microsoft Computer Dictionary, Fifth Edition

adj. One by one. For example, in serial transmission, information is transferred one bit at a time; a serial computer has only one arithmetic logic unit, which must execute the whole program one step at a time. Compare parallel (definition 3).

serial access

n. See sequential access.

serial adder

n. A circuit that adds two numbers one bit position (one digit place) at a time.

serial communication

n. The exchange of information between computers or between computers and peripheral devices one bit at a time over a single channel. Serial communications can be synchronous or asynchronous. Both sender and receiver must use the same baud rate, parity, and control information. See also baud rate, parity, start bit, stop bit.

Serial Infrared

n. A system developed by Hewlett-Packard for transmitting data between two devices up to 1 meter apart using an infrared light beam. Infrared ports on the receiving and the sending devices must be aligned. Generally, Serial Infrared is used with laptops and many notebook computers, as well as with peripherals such as printers. Acronym: SIR. See also infrared port.

serial interface

n. A data transmission scheme in which data and control bits are sent sequentially over a single channel. In reference to a serial input/output connection, the term usually implies the use of an RS-232 or RS-422 interface. See also RS-232-C standard, RS-422/423/449. Compare parallel interface.

serialize

vb. To change from parallel transmission (byte by byte) to serial transmission (bit by bit). Compare deserialize.

SerialKey device

n. Enables you to attach an alternative input device (also called an augmentative communication device) to your computer’s serial port. This feature is designed for people who are unable to use the computer’s standard keyboard and mouse.

SerialKeys

n. A feature of Windows 9x, Windows NT, Windows 2000, and Windows XP that, in conjunction with a communications aid interface device, allows keystrokes and mouse controls to be accepted through a computer’s serial port.

Serial Line Internet Protocol n. See SLIP.

serial mouse

n. A pointing device that attaches to the computer through a standard serial port. See also mouse. Compare bus mouse.

serial port

n. An input/output location (channel) that sends and receives data to and from a computer’s central processing unit or a communications device one bit at a time. Serial ports are used for serial data communication and as interfaces with some peripheral devices, such as mice and printers.

serial port adapter

Microsoft Computer Dictionary, Fifth Edition

n. An interface card or device that either provides a serial port or converts a serial port to another use. See also adapter, serial port.

serial printer

n. A printer connected to the computer via a serial interface (commonly RS-232-C or compatible). Connectors for this type of printer vary widely, which is one reason they are less popular than parallel printers among those who use IBM and IBM-compatible PCs. Serial printers are standard for Apple computers. See also DB connector, serial, serial transmission. Compare parallel printer.

serial processing

n. See sequential processing (definition 2).

Serial Storage Architecture n. See SSA.

serial transmission

n. The transfer of discrete signals one after another. In communications and data transfer, serial transmission involves sending information over a single line one bit at a time, as in modem-to- modem connections. Compare parallel transmission.

series circuit

n. A circuit in which two or more components are linked in series. All the current passes through each component in a series circuit, but the voltage is divided among the components. See the illustration. Compare parallel circuit.

Series circuit.

serif1

adj. Marked by the use of serifs. For example, Goudy is a serif typeface, whereas Helvetica is a sans serif typeface. See the illustration. See also serif2. Compare sans serif.

Serif. A serif typeface (top) and a sans serif typeface (bottom).

serif2

n. Any of the short lines or ornaments at the ends of the strokes that form a typeface character.

server

n. 1. On a local area network (LAN), a computer running administrative software that controls access to the network and its resources, such as printers and disk drives, and provides resources

Microsoft Computer Dictionary, Fifth Edition

to computers functioning as workstations on the network. 2. On the Internet or other network, a computer or program that responds to commands from a client. For example, a file server may contain an archive of data or program files; when a client submits a request for a file, the server transfers a copy of the file to the client. See also application server (definitions 1 and 2), client/server architecture. Compare client (definition 3).

server appliance

n. A device designed to deliver one or more specific network services in a single turnkey package that includes both hardware and software. All necessary programs are preinstalled on a server appliance, which has minimal, simplified options and controls. Server appliances can be used to complement or replace traditional servers on a network and can provide such services as file and printer sharing and Internet connectivity. Also called: appliance. See also information appliance.

server-based application

n. A program that is shared over a network. The program is stored on the network server and can be used at more than one client machine at a time.

server cluster

n. A group of independent computer systems, known as nodes, working together as a single system to ensure that mission-critical applications and resources remain available to clients. A server cluster is the type of cluster that Cluster service implements. See also cluster.

server control

n. See ASP.NET server control.

server error

n. A failure to complete a request for information through HTTP that results from an error at the server rather than an error by the client or the user. Server errors are indicated by HTTP status codes beginning with 5. See also HTTP, HTTP status codes.

server farm

n. A centralized grouping of network servers maintained by an enterprise or, often, an Internet service provider (ISP). A server farm provides a network with load balancing, scalability, and fault tolerance. Individual servers may be connected in such a way that they appear to represent a single resource.

serverlet

n. See servlet.

Server Message Block n. See SMB.

server push-pull

n. A combination of Web client/server techniques individually called “server push” and “client pull.” In server push, the server loads data to the client, but the data connection stays open. This allows the server to continue sending data to the browser as necessary. In client pull, the server loads data to the client, but the data connection does not stay open. The server sends an HTML directive to the browser telling it to reopen the connection after a certain interval to get more data or possibly to open a new URL. See the illustration. See also HTML, server (definition 2), URL.

Microsoft Computer Dictionary, Fifth Edition

Server push-pull.

server-side include

n. A mechanism for including dynamic text in World Wide Web documents. Server-side includes are special command codes that are recognized and interpreted by the server; their output is placed in the document body before the document is sent to the browser. Server-side includes can be used, for example, to include the date/time stamp in the text of the file. Acronym: SSI. See also server (definition 2).

service

n. 1. A customer-based or user-oriented function, such as technical support or network provision. 2. In reference to programming and software, a program or routine that provides support to other programs, particularly at a low (close to the hardware) level. 3. In networking, specialized, software-based functionality provided by network servers—for example, directory services that provide the network equivalent of “phone books” needed for locating users and resources. See also utility.

Service Advertising Protocol

n. A method used by a service-providing node in a network (such as a file server or application server) to notify other nodes on the network that it is available for access. When a server boots, it uses the protocol to advertise its service; when the same server goes off line, it uses the protocol to announce that it is no longer available. Acronym: SAP. See also server (definition 1).

service bureau

n. 1. A company that provides various services related to publishing, such as prepress production, desktop publishing, typesetting, imagesetting, and optical scanning of graphics. 2. An organization that provides data processing services and access to software packages for a fee.

service provider n. See ISP.

servlet or servelet

n. A small Java program that runs on a server. The term is a companion to applet, a Java program that usually runs on the client. Servlets perform lightweight Web services, such as redirecting a Web user from an outdated address to the correct page—tasks traditionally handled by CGI (Common Gateway Interface) applications. Because servlets are automatically threaded and highly responsive, they execute quickly, thereby reducing system overhead. Also called: serverlet. See also applet, CGI.

servlet container

n. In Sun Microsystems’s J2EE network platform, a container that decodes requests, formats responses, and provides the network services over which requests and responses are sent. All servlet containers must support HTTP as a protocol for requests and responses, but they may also support additional request-response protocols such as HTTPS. See also container, HTTP, HTTPS, J2EE.

servo

Microsoft Computer Dictionary, Fifth Edition

n. The part of a servomechanism, controlled by the servomechanism’s feedback circuit, that produces the final mechanical output. Also called: servomotor. See also servomechanism.

servomechanism

n. A control system in which the final output is mechanical movement. A servomechanism uses feedback to control the position, velocity, or acceleration of a mechanical component. Also called: servo system.

servomotor n. See servo.

servo system

n. See servomechanism.

session

n. 1. The time during which a program is running. In most interactive programs, a session is the time during which the program accepts input and processes information. 2. In communications, the time during which two computers maintain a connection. 3. A specific protocol layer in the ISO/OSI reference model that manages communication between remote users or processes. See also ISO/OSI reference model, session layer.

session bean

n. In the Java programming language and J2EE network platform, an enterprise bean that is created by a client and usually exists only for the duration of a single client/server session. It performs operations, such as calculations or accessing a database, for the client. While a session bean may be transactional, it is not recoverable should a system crash occur. Session bean objects can either be stateless or can maintain conversational state across methods and transactions. If a session bean maintains state, the Enterprise JavaBean (EJB) container manages this state if the object must be removed from memory. However, the session bean object itself must manage its own persistent data. See also EJB, stateless.

session layer

n. The fifth of seven layers in the ISO/OSI reference model. The session layer handles the details that must be agreed on by the two communicating devices. See the illustration. See also ISO/OSI reference model.

Session layer.

Microsoft Computer Dictionary, Fifth Edition

set1

n. In printing and display, a group of related characters, such as a character set. See also character set.

set2

vb. 1. To change the value of a bit to 1. 2. To establish a particular condition, such as setting tab stops, setting a counter to 0, or setting a breakpoint. See also breakpoint.

SET protocol

n. See Secure Electronics Transactions protocol.

settling time

n. The time required for a disk drive’s read/ write head to stabilize over a new location on the disk after being moved.

set-top box

n. A device that converts a cable TV signal to an input signal to the TV set. Set-top boxes can be used to access the World Wide Web and are a type of information appliance. See also information appliance.

setup

n. 1. A computer along with all its devices. 2. The procedures involved in preparing a software program or application to operate within a computer.

setup program

n. 1. A built-in BIOS program for reconfiguring system parameters to accommodate a new disk drive. See also BIOS. 2. See installation program.

setup string

n. See control code.

setup wizard

n. In Windows, a utility that asks users a structured series of questions and gives them options to aid the process of installing a new program.

seven-segment display

n. A light-emitting diode (LED) display or liquid crystal display (LCD) that can show any of the 10 decimal digits. The seven segments are the seven bars that form a numeral 8 as in a calculator display.

sex changer

n. See gender changer.

sfx

n. A computer language used to generate digital audio effects and synthesizer instrument audio. It is a superset of the MPEG-4 standard SAOL audio compiler language. Sfx provides professional-quality audio synthesis, real-time MIDI and audio generation, and fully customizable instruments and effects. Because the sfx compiler is a C++ front-end compiler, code is converted to C++ and then compiled into executable orchestras that are used to generate real-time audio. As a result, the current release of sfx requires that Microsoft Visual C++ be installed on the system on which sfx is running. See also C++, compiler, MIDI, MPEG-4, SAOL, Visual C++.

.sgm

n. The MS-DOS/Windows 3.x file extension that identifies files encoded in Standard Generalized Markup Language (SGML). Because MS-DOS and Windows 3.x cannot recognize file extensions

Microsoft Computer Dictionary, Fifth Edition

longer than three letters, the .sgml extension is truncated to three letters in those environments. See also SGML.

.sgml

n. The file extension that identifies files encoded in Standard Generalized Markup Language. See also SGML.

SGML

n. Acronym for Standard Generalized Markup Language. An information management standard adopted by the International Organization for Standardization (ISO) in 1986 as a means of providing platformand application-independent documents that retain formatting, indexing, and linked information. SGML provides a grammarlike mechanism for users to define the structure of their documents and the tags they will use to denote the structure in individual documents. See also ISO.

SGRAM

n. See synchronous graphics RAM.

sh

n. See Bourne shell.

SHA

n. Acronym for Secure Hash Algorithm. A technique that computes a 160-bit condensed representation of a message or data file, called a message digest. The SHA is used by the sender and the receiver of a message in computing and verifying a digital signature, for security purposes. See also algorithm, digital signature.

shade1

n. A particular color variation produced by mixing black with a pure color. See also brightness, IRGB.

shade2

vb. To give added dimension to an image by including changes in appearance caused by light and shadow. See also color model.

shadow mask

n. A type of mask used in cathode ray tube (CRT) monitors in which an opaque sheet perforated by tiny pinholes ensures that the electron beam for a particular color strikes only the phosphor it is supposed to illuminate. Like the aperture grill, which relies on vertical stripes, and the slot mask, which is based on elliptical openings, a shadow mask helps create a clear, sharp image by narrowly focusing the electron beam. See also CRT, mask (definition 2). Compare aperture grill, slot mask.

shadow memory

n. A technique employed by the BIOS in some 80x86-based computers to copy the system’s ROM BIOS routines into an unused section of RAM during the computer’s startup process. This helps boost system performance by diverting system requests for the BIOS routines to their “shadow” copies. Also called: shadow RAM, shadow ROM.

shadow print

n. A style applied to text in which a duplicate of each character is shifted, typically down and to the right, to create a shadow effect. See the illustration.

Microsoft Computer Dictionary, Fifth Edition

Shadow print.

shadow RAM

n. See shadow memory.

shadow ROM

n. See shadow memory.

share

vb. To make files, directories, or folders accessible to other users over a network.

shared assembly

n. An assembly that can be referenced by more than one application. An assembly must be explicitly built to be shared by giving it a cryptographically strong name. See also private assembly, strong name.

shared directory

n. See network directory.

shared folder

n. On a Macintosh computer connected to a network and running System 6.0 or higher, a folder that a user has made available to others on the network. A shared folder is analogous to a network directory on a PC. See also network directory.

shared logic

n. The use, by multiple circuits or software routines, of common circuits or routines to implement an operation.

shared medium

n. The communications medium shared by network nodes; essentially, the network bandwidth.

shared memory

n. 1. Memory accessed by more than one program in a multitasking environment. 2. A portion of memory used by parallel-processor computer systems to exchange information. See also parallel processing.

shared name

n. See strong name.

shared network directory n. See network directory.

shared printer

Microsoft Computer Dictionary, Fifth Edition

n. A printer that receives input from more than one computer.

shared resource

n. 1. Any device, data, or program used by more than one device or program. 2. On a network, any resource made available to network users, such as directories, files, and printers.

SharePoint team Web site

n. A customizable Web site with features that help a team work together. The default site has pages for document libraries, announcements, and team events. Only members, specified by the site creator, can use the site.

shareware

n. Copyrighted software that is distributed on a try-before-you-buy basis. Users who want to continue using the program after the trial period are encouraged to send a payment to the program’s author. Compare free software, freeware, public-domain software.

sharpness

n. See resolution (definition 1).

sheet

n. A feature for handling dialog boxes included in the Mac OS X Aqua interface. When the user chooses to save or print a document, a translucent sheet emerges from the window title bar and remains attached to that window even if it is moved to the background. The sheet allows the user to continue working in the window, or in other windows, without closing the sheet.

sheet-fed scanner

n. A scanner with a single-sheet feed mechanism, in which sheets of paper are pulled in by the scanner and scanned as they pass over a stationary scanning mechanism. Sheet-fed scanners allow for automatic scanning of multiple-sheet documents. See also scanner. Compare drum scanner, flatbed scanner, handheld scanner.

sheet feeder

n. A device that accepts a stack of paper and feeds it to a printer one page at a time.

shelfware

n. Software that has been unsold or unused for a long time, and so has remained on a retailer’s or user’s shelf.

shell1

n. A piece of software, usually a separate program, that provides direct communication between the user and the operating system. Examples of shells are Macintosh Finder and the MS-DOS command interface program COMMAND.COM. See also Bourne shell, C shell, Finder, Korn shell. Compare kernel.

shell2

vb. See shell out.

shell account

n. A computer service that permits a user to enter operating-system commands on the service provider’s system through a command-line interface (usually one of the UNIX shells) rather than having to access the Internet through a graphical user interface. Shell accounts can provide Internet access through character-based tools such as Lynx for browsing the World Wide Web. See also shell1.

shell archive