technology terminology 091

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Technology TerminologyQuick Index - Clicking on a letter jumps to the Technology Termsstarting with that letter.

ABCDEFGHIJKLMNOPQRSTUVWXYZ

If you are aware of a term missing from this listing, please send the term

and its definition information via E-mail to

[email protected]

A or Return to Quick Index

ABI/InformA database of articles in more than 800 business-related periodicals and specialty

publications since 1986.

Access Provider


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The company that provides you with Internet access and, in some cases, an onlineaccount on their computer system.

Acoustic CouplerA type of modem which converts digital signals into sound for transmission through

telephone lines, and performs the reverse operation when receiving such signals.

Acoustic couplers generally have cups for the telephone handset.Active WindowThe top or front window in a multiple window environment.

A/D ConverterA device used to convert analog data to digital data. Analog data is continuously variable,

while digital data contains discrete steps.

Additive PrimariesRed, green, and blue are the primary colors of light from which all other colors can bemade.

Address ResolutionConversion of an IP Address to the corresponding low-level physical address.

AIX Advanced Interactive Executive - IBM's version of Unix.

AliasingVisibly jagged steps along angled or object edges, due to sharp tonal contrasts between

pixels.

AnalogContinuously variable signals or data.

Anonymous Login Convention (FTP)Standard username (anonymous) and password (guest) which allows login within FTP forthe purpose of retrieving an unprotected file.

ANSIAmerican National Standards Institute. This organization is responsible for approving

U.S. standards in many areas, including computers and communications. Standardsapproved by this organization are often called ANSI standards (e.g., ANSI C is the

version of the C language approved by ANSI).

Application

Software that lets users do relatively complex tasks, as well as create and modifydocuments. Common application types include word processors, spreadsheets, database

managers, and presentation graphics programs.

ARA

AppleTalk Remote Access. A protocol (and product) that provides system-level supportfor dial-in (modem) connections to an AppleTalk network. With ARA, you can call your

desktop Mac from a PowerBook and remotely access all the available services - files,printers, servers, e-mail, etc.

ArchieAn information system offering an electronic directory service for locating information in

the Internet that is automatically updated. The best known use of archie is for scanning adatabase of the contents of more than 1000 Anonymous FTP sites around the world with

more than 2,100,000 file names.

ARP


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Address Resolution Protocol. Used to dynamically discover the low-level physicalnetwork hardware address that corresponds to the high level IP Address for a given host,

for instance. ARP is limited to physical network systems that support broadcast packetsthat can be heard by all hosts on the network. See also Proxy ARP.

ARPANET

Advanced Research Projects Agency NETwork. A pioneering long-haul network fundedby ARPA, an agency of the US Department of Defense responsible for the developmentof new technology for the military. It served as the basis for early networking research as

well as a central backbone during the development of the Internet. The ARPANETconsisted of individual packet switching computers interconnected by leased lines.

ASCIIAmerican (National) Standard Code for Information Interchange. A standard character-

to-number encoding widely used in the computer industry.

Associate

Linking a document with the program that created it so that both can be opened with asingle command.

AV Audio-Visual. AV Macintosh models have video-capture hardware and have

sophisticated sound (and video) recording capabilities.

AU soundsA type of audio format used in the World Wide Web.

B or Return to Quick Index

B

ByteOne character of information, usually eight bits wide.

BackboneNetwork used to interconnect several networks together.

Backup fileIn Windows 95, a compressed version of the original file and its locations created by

Backup.

Bandwidth

The capacity of the transmission medium stated in bits per second or as a frequency. Thebandwidth of optical fiber is in the gigabit or billion bits per second range, while ethernet

coaxial cable is in the megabit or million bits per second range.

Baseband SystemA baseband system transmits signals without converting them to another frequency and is

characterized by its support of one frequency of signals. Ethernet-based networks insidecampus buildings are transmitted via baseband coaxial cable, with ethernet being the only

service supported by the coaxial cable.

BAT

Filename extension for a batch file.

Batch Scanning


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Sequential scanning of multiple originals using previously defined, unique settings foreach.

BaudA unit of measurement that denotes the number of bits that can be transmitted per second.

For example, if a modem is rated at 9600 baud it is capable of transmitting data at a rate

of 9600 bits per second. The term was derived from the name of J.M.E. Baudot, a Frenchpioneer in the field of printing telegraphy.

BBS

Bulletin Board Service. A non commercial dial-up service usually run by a user group orsoftware company. By dialing up a BBS with your modem, you can exchange messages

with other users, and upload or download software.

BGI

Binary Gateway Interface. Provides a method of running a program from a Web server.Similar to a Common Gateway Interface (CGI). The BGI uses a binary DLL which is

loaded into memory when the server starts. While more efficient han a CGI, the BGImust be compiled and is not easily portable to other environments.

BilevelA type of image containing only black and white pixels.

BinaryA numbering system with only two values: 0 (zero) and 1 (one).

Binary FileA file that contains more than plain text (i.e., photos, sounds, spreadsheet, etc.) In

contrast to an ASCII file which only contains plain text.

Binary Number SystemA counting system used in computers consisting of only 1's and 0's (zeros).

BinHex

A file conversion format that converts binary files to ASCII test files.

BIOS

Basic Input-Output System. Part of the computer's operating system that is built into themachine, rather than read from a disk drive at startup.

bitA unit of measurement that represents one figure or character of data. A bit is the

smallest unit of storage in a computer. Since computers actually read 0s and 1s, each ismeasured as a bit. The letterA consists of 8 bits which amounts to one byte. Bits are

often used to measure the capability of a microprocessor to process data, such as 16-bit or32-bit.

Bit DepthThe number of bits used to represent each pixel in an image, determining its color or

tonal range.

Bit-map

Generally used to describe an illustration or font file as being created by a predefinednumber of pixels. Also see Object-oriented.

BITNETAn academic computer network that provides interactive electronic mail and file transfer

services, using a store-and-forward protocol, based on IBM Network Job Entry protocols.BITNET-II encapsulates the BITNET protocol within IP packets and depends on the


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Internet to route them. There are three main constituents of the network: BITNET in theUnited States and Mexico, NETNORTH in Canada, and EARN in Europe. There are also

AsiaNet, in Japan, and connections in South America. See CREN.

Black PointA movable reference point that defines the darkest area in an image, causing all other

areas to be adjusted accordingly.BootingStarting up a computer via the power switch, which loads the system software into

memory. Restarting the computer via a keystroke combination is called rebooting or awarm boot.

BridgeA dedicated computer used to connect two different networks. It uses data link layer

address (i.e., ethernet physical addresses) to determine if packets should be passedbetween the networks.

Broadband SystemA broadband system is capable of transmitting many different signals at the same time

without interfering with one another. For local area networks, a broadband system is onethat handles multiple channels of local area network signals distributed over Cable

Television (CATV) hardware.

Broadcast

A packet whose special address results in its being heard by all hosts on a computernetwork.

BrowserA program that enables you to access information on the Internet through the World

Wide Web.

bps

Bits Per Second is the unit used for measuring line speed, the number of informationunits transmitted per second.

BSDBerkeley Software Distribution. Implementation of the UNIX operating system and its

utilities developed and distributed by the University of California at Berkeley. BSD isusually preceded by the version number of the distribution, e.g., 4.3 BSD is version 4.3 of

the Berkeley UNIX distribution. Many Internet hosts run BSD software, and it is theancestor of many commercial UNIX implementations.

BugA mistake, or unexpected occurrence, in a piece of software or in a piece of hardware.

ByteThe amount of memory needed to store one character such as a letter or a number. Equal

to 8 bits of digital information. The standard measurement unit of a file size.

C or Return to Quick Index


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CacheAn area of RAM reserved for data recently read from disk, which allows the processor to

quickly retrieve it if it's needed again.

CachingA process in which frequently accessed data is kept on hand, rather than constantly being

from the place where it is stored.Case-dependentSoftware differentiation between upper and lower case characters. Also referred to as

case sensitive.

CCDCharge-coupled device. An integrated, micro-electrical light sensing device built intosome image capturing devices.

CD-ROMCompact Disk, Read-Only Memory. A type of storage device that looks just like an audio

CD and stores as much data as a large hard disk (600MB), making it a popular means ofdistributing fonts, photos, electronic encyclopedias, games, and multimedia offerings. As

the name indicates, however, you can't save or change files on a CD-ROM, only readthem. Pronounced see-dee rom.

CGICommon Gateway Interface. A method of running an executable script or program from

a Web server. When a client requests a URL pointing to a CGI, the program is run andthe results are returned to the client. This enables dynamic web pages and the ability to

do database queries and other complex operations across the web

CIEThe "Commission Internationale de l'Eclairage". An organization that has established anumber of widely-used color definitions.

Circuit-switchedA type of network connection which establishes a continuous electrical connection

between calling and called users for their exclusive use until the connection is released.Ericsson PBX is a circuit-switched network.

Clickable ImageAny image that has instructions embedded in it so that clicking on it initiates some kind

of action or result. On a web page, a clickable image is any image that has a URLembedded in it.

Client/server relationshipA client application is one that resides on a user's computer, but sends requests to a

remote system to execute a designated procedure using arguments supplied by the user.The computer that initiates the request is the client and the computer responding to the

request is the server. Many network services follow a client and server protocol.

ClipboardAn area used to temporarily store cut or copied information. The Clipboard can store text,graphics, objects, and other data. The Clipboard contents are erased when new

information is placed on the Clipboard or when the computer is shut down.

Clipping


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The conversion of all tones lighter than a specified grey level to white, or darker than aspecified grey level to black, causing loss of detail. This also applies to individual

channels in a color image.

CMSColor management system. This ensures color uniformity across input and output devices

so that final printed results match originals. The characteristics or profiles of devices arenormally established by reference to standard color targets.

CMYKCyan, magenta, yellow, and black are the base colors used in printing processes. CMYare the primary colorants of the subtractive color model.

ColorimeterA light-sensitive device for measuring colors by filtering their red, green, and blue

components, as in the human eye. See also spectrophoto-meter.

Color CastAn overall color imbalance in an image, as if viewed through a colored filter.

COM1, COM2, etc. -

Most serial ports and internal modems on DOS/WIN PCs can be configured to eitherCOM1 or COM2 in order to accommodate the situation where both may exist. The DOS

MODE command is used to change the output direction to such serial devices asmodems.

CompressionThe reduction in size of an image file. See also lossy and non-lossy.

Computer Search ServiceComputer Search Service (CSS), a fee-based service, offers access to more than 500

databases, primarily in the sciences and social sciences, from which the Library cancreate customized bibliographies.

Configuration1. The components that make up a computer system (which model and what peripherals).

2. The physical arrangement of those components (what's placed and where). 3. Thesoftware settings that enable two computer components to talk to each other (as in

configuring communications software to work with a modem).

Contone (CT)An abbreviation for continuous tone. A color or greyscale image format capable ofillustrating continuously varying tonal ranges, as opposed to line art.

CookiesA file sent to a web browser by a web server that is used to record once's activities.

CoprocessorA chip designed specifically to handle a particular task, such as math calculations or

displaying graphics on-screen. A coprocessor is faster at its specialized function than themain processor is, and it relieves the processor of some work. A coprocessor can reside

on the motherboard or be part of an expansion card, as with an accelerator.

Coaxial CableA type of cable that contains two conductors. The center conductor is surrounded by alayer of insulation, which is then wrapped by a braided-metal conductor and an outer

layer of insulation.

CPU


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Central Processing Unit; the brains of the computer. The CPU interprets and executes theactual computing tasks.

CrashA problem (often caused by a bug) that causes a program, or the entire operating system,

to unexpectedly stop working.

CRENCorporation for Research and Educational Networking. This organization was formed inOctober 1989, when BITNET and CSNET (Computer + Science NETwork) were

combined under one administrative authority. CSNET is no longer operational, butCREN still runs BITNET. See BITNET.

Cross-platformRefers to software (or anything else) that will work on more that one platform (type of

computer).

CSUNETCalifornia State University Network. A packet-switched network that connects the 22campuses of the CSU system.

CursorThe representation of the mouse on the screen. It may take many different shapes.

Example: I-beam, arrow pointer, and hand.

Cyberspace

A term used to refer to the electronic universe of information available through theInternet.

D or Return to Quick Index

DATDigital Audio Tape. The most common type of tape backup.

DaughterboardA board that attaches to (rides piggyback on) another board, such as the motherboard or

an expansion card. For example, you can often add a daughtercard containing additionalmemory to an accelerator card.

DatabaseA file created by a database manager that contains a collection of information organized

into records, each of which contains labeled categories (called fields).

DCSDesktop color separation. An image format consisting of four separate CMYK PostScriptfiles at full resolution, together with a fifth EPS master for placement in documents.

DDNDefense Data Network. A global communications network serving the US Department ofDefense composed of MILNET, other portions of the Internet, and classified networks

which are not part of the Internet. The DDN is used to connect military installations andis managed by the Defense Information Systems Agency (DISA).

DECDigital Equipment Corporation.

Decompression


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The expansion of compressed image files. See also lossy and non-lossy.

Dedicated line

A telephone or data line that is always available. For example, a leased telephone line canbe dedicated for computer data communications. This line is not used by other computers

or individuals, is available 24 hours a day, and is never disconnected.

Default RouteA routing table entry which is used to direct packets addressed to networks not explicitlylisted in the routing table.

DensitometerA measuring instrument that registers the density of transparent or reflective materials.

Colors are read as tonal information. See also colorimeter and spectrophotometer.

Density

Density is a brightness control to lighten or darken a printout to more closely reflect itsscreen appearance and to compensate for deficiencies in toner or paper quality.

DescreeningRemoval of halftone dot patterns during or after scanning printed matter by defocusing

the image. This avoids moire patterning and color shifts during subsequent halftonereprinting.

Dialog boxA window that displays additional options or questions when a command is chosen.

Dial-up lineA communication connection from your computer to a host computer over standard

phone lines. Unlike a dedicated line, you must dial the host computer in order to establisha connection. Dial-up line is currently the most popular form of Net connection for the

home user.

Dichroic MirrorA special type of interference filter, which reflects a specific part of the spectrum, whilsttransmitting the rest. Used in scanners to split a beam of light into RGB components.

DigitalData or voltages consisting of discrete steps or levels, as opposed to continuously

variable analog data.

Digital CameraA video or still camera that records images digitally to be viewed by a computer. You can

then open the image on the computer and edit it any way you like.

DigitizersA machine which converts analog data into digital data on a computer (such as a scanner

digitizing pictures or text).

DIP switchesDual Interface Poll switches allow for either an ON or OFF setting with any number ofcircuits. DIP switches commonly allow you to change the configuration of a circuit board

to suit your particular computer.

Direct connectionA permanent communication connection between your computer system (either a singleCPU or a LAN) and the Internet. This is also called a leased line connection because you


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are leasing the telephone connection from the phone company. A direct connection is incontrast to a SLIP/PPP or dial-up connection.

Direct-To-PlateDirect exposure of image data onto printing plates, without the intermediate use of film.

Direct-To-Press

Elimination of intermediate film and printing plates by the direct transfer of image data toprinting cylinders in the press.

DirectoryA system that your computer uses to organize files on the basis of specific information.

Disk Defragmenter

Arranges the blocks of information for a file into adjacent blocks on your hard drive,which may significantly improve the file access times.

DmaxThe point of maximum density in an image or an original.

DminThe point of minimum density in an image or an original.

DNS Domain Name System. A general purpose distributed, replicated, data query service. Its

principal use is the lookup of host IP addresses based on host names. The host names arealso known as domain names. Some important domains are: .COM (commercial), .EDU

(educational), .NET (network operations), .GOV (U.S. government), and .MIL (U.S.military). Most countries also have a domain. For example, .US (United States), .UK

(United Kingdom), .AU (Australia).

Domain Name ServerA computer that converts host names, such as rohan.sdsu.edu to its corresponding IPAddress, such as 191.130.1.10. An SDSU computer provides this service any time mail is

sent or received and permits users to use TELNET and FTP between SDSU and othersites.

DOSDisk Operating System. The operating system used on IBM personal computers and

compatible machines.

Dotted Decimal Notation

The convention for writing 32-bit IP Addresses as a set of four 8-bit numbers written inbase 10 with periods separating them.

Down-SamplingThe reduction in resolution of an image, necessitating a loss in detail.

DownloadTo retrieve a file from another computer using a modem.

dpiDots Per Inch. A measure of the resolution of a printer, scanner, or monitor. It refers to

the number of dots in a one-inch line. The more dots per inch, the higher the resolution.

DriverA piece of software that tells the computer how to operate an external device, such as aprinter, hard disk, CD-ROM drive, or scanner. For instance, you can't print unless you

have a printer driver. Hard disk drivers are invisible files that are loaded into memory


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when you start the computer, while scanner drivers are usually plug-ins accessed fromwithin a particular application.

Drum ScannerEarly drum scanners separated scans into CMYK data, recording these directly onto film

held on a second rotating drum.

DTP Desktop Publishing.

DumpBack-up of data.

Duplex (Full, Half)Full duplex is data is flowing in both directions at the same time. When Remote echo isON communication is occurring in full duplex. Half Duplex has data moving in only one

direction at a time (Local echo is ON).

DXFDrawing Interchange Format used for Macintosh graphic files. The standard file-exchange format for 3-D and CAD programs.

Dye SublimationA printing process using small heating elements to evaporate pigments from a carrier

film, depositing these smoothly onto a substrate.

E or Return to Quick Index

EARNEuropean Academic Research Network.

Echo (Local, Remote)Local echo ON causes all transmitted data to be sent to the screen of the sendingcomputer. Remote echo ON causes everything that the remote computer (the one you are

communicating with) transmits to be duplicated on your computer's screen. See Duplex.

EBCDICExtended Binary-Coded Decimal Interchange Code. A standard character-to-numberencoding used primarily by IBM computer systems. See ASCII.

E-mailElectronic Mail. Private messages sent between users on different computers, either over

a network or via a modem connection to an on-line service or BBS.

Encoding

File transfer formatting that enables encrypted, compressed or binary files to betransferred without corruption or loss of data.

EncryptionA way of coding information in a file or e-mail message so that if it is intercepted by athird party as it travels over a network it cannot be read.

EPSEncapsulated PostScript. An EPS file usually has two parts: a PostScript (text)

description that tells a PostScript printer how to output the resolution-independent image,and (optionally) a bit-mapped PICT image for on-screen previews. (EPS files without a


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PICT preview is usually displayed as a gray rectangle.) EPS files generally can't beedited, even by the program that created them (Illustrator files are exceptions).

EPS 5Another term used for DCS.

ERIC

An index to educational journal articles and documents collected by national clearinghouses for educational information. It provides summaries of the articles and documents,and contains citations back to 1966.

EthernetAn IEEE 802.3 standard data link layer which can operate over several different media

including fiber optic, coaxial cable and twisted-pair cable. This 10 million-bit-per-secondnetworking scheme is widely used on campus because it can network a wide variety of

computers; it is not proprietary; and components are widely available from manycommercial sources.

Executable FileRefers to a file that is a program. Executables in DOS and Windows usually have an .exe

or a .com extension. In UNIX and Macintosh environments, executable files can have anyname.

External viewerProgram used for presenting graphics, audio and movies while browsing World Wide

Web pages via a Web client program. Helper applications is another term for theseexternal programs.

F or Return to Quick Index

FAQFrequently Asked Questions. A document that covers a topic of general concern to many

users. FAQs are a good way for new users to get information on various aspects of theInternet.

FDDIFiber Distributed Data Interface. An emerging standard for network technology based on

fiber optics that has been established by the American National Standards Institute(ANSI). FDDI specifies a 100-million bit per second data rate.

FileA collection of information on a disk, usually a document or a program, that's lumped

together and called by one name.

File PermissionsWhen you place files on a UNIX system you can assign the files various levels of

permission, specifying who can access them, and what type of access they can have.

File ServerA computer that shares its resources, such as printers and files, with other computers onthe network. An example of this is a Novell NetWare Server which shares its disk space

with a workstation that does not have a disk drive of its own.

Film Recorder


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Used in reference to color transparency recording devices, and sometimes also toimagesetters.

FilterA piece of software that an application uses for file-format conversion or special effects.

PageMaker, for example, has a filter that lets it import Microsoft Word files, while

Photoshop has dozens of filters for special effects (such as image blurring). Filters can bepart of the main application or external programs called plug-ins.

FingerA program that displays information about someone on the internet.

Firewall

A mechanism that isolates a network from the rest of the Internet, permitting onlyspecific traffic to pass in and out.

Flaming/Flame WarReacting to someone's newsgroup posting or e-mail in a hostile manner by publicly

chastising the person or bombarding the person with nasty e-mail.

Flatbed Scanner

Any scanning device that incorporates a flat transparent plate, on which original imagesare placed for scanning. The scanning process is linear rather than rotational.

Floating-point ProcessorA special chip that handles sophisticated calculations, such as those used in spreadsheets,

CAD, and scientific programs.

Floppy DiskA portable data storage device. The most common disks are 3 1/2" but there are still old 51/4" disks around. Floppy disks can store up to 1.44 megabytes of information and allow

you to transfer information from computer to computer without any connections.

FolderAn object that can hold other objects, such as other folders and files.

FontThe software that creates a typeface on a computer screen.

FormatTo initialize a disk to prepare it for use. The disk is checked for errors and organized sothat data can be recorded and retrieved. Formatting a used disk erases any previously

stored information.

FPOFor Position Only. A low resolution image placed in a document to indicate where thefinal version is to be positioned.

FragmentationA condition where parts of a file are stored in different locations on a disk. When a file is

fragmented, the drive's read/write head has to jump from place to place to read the data; ifmany files are fragmented, it can slow the drive's performance.

Frame-grabbing SystemA combination of hardware and software, designed to capture individual frames from

video clips for further digital manipulation, or consecutive replay on computer platforms.

FTPFile Transfer Protocol. The Internet standard high-level protocol for transferring filesfrom one computer to another across the network.


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FTP siteA computer which stores files that can be retrieved using FTP. FTP sites which allow

anyone to retrieve files (without having an account on that computer) are known asAnonymous FTP sites.

G or Return to Quick Index

Gamma CorrectionThe correction of tonal ranges in an image, normally by the adjustment of tone curves.

GamutThe limited range of colors provided by a specific input device, output device or pigment

set.

Gang ScanningSequential scanning of multiple originals using the same previously defined exposuresetting for each.

GatewayA special-purpose dedicated computer that attaches to two or more disparate networks

and converts data packets from one form to another.

GBGigabyte. A unit of data storage size which represents 10^9 (one billion) characters ofinformation.

GbGigabit. 10^9 bits of information (usually used to express a data transfer rate; as in, 1

Gigabit/second = 1Gbps).

GCG (Grey Component Replacement)A technique for replacing all the neutral tones of an image with an appropriate amount ofblack.

GIFGraphic Interchange Format (pronouncedjiff). A file compression format developed by

CompuServe for transferring graphic files to and from on-line services.

Gigabyte1,024 megabytes, or 1,048,576 kilobytes of digital data.

gopherA consistent user interface and gateway into many on-line white pages and other addressdatabases.

Graphical User Interface (GUI)The graphical visual representation of the working environment that presents theelements of your computer as objects on a desktop.

Grey BalanceThe balance between CMY colorants required to produce neutral greys without a color

cast.

Grey LevelsDiscrete tonal steps in a continuous tone image, inherent to digital data. Most CT imageswill contain 256 grey levels per color.

Greyscale


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A continuous tone image comprising black, white, and grey data only.

H or Return to Quick Index

Hacker

Slang term for a technically sophisticated computer user who enjoys exploring computersystems and programs, sometimes to the point of obsession.

HalftoneA simulation of continuous tones by the use of black or overlapping process color dots of

varying size or position.

Halftoning FactorSee quality factor.

HaloA light line around object edges in an image, produced by the USM (sharpening)

technique.HandleUnique character string identifier assigned to each entry in the NIC WHOIS database.

HandshakingThe process computers and modems go through in order to establish a connection and

agree on the speed and protocols for data transmission.

Hard Drive or (Hard Disk)The permanent storage disk inside your computer. Software and other data is stored here.The size of hard drives are now typically measured in gigabytes.

HardwareAny peripheral equipment, mechanical or electrical, that can be connected to the

computer. For instance; printers, scanners, modems, CPU's, disks.Hayes CompatibleA modem is considered Hayes Compatible if it supports the Hayes command set (alanguage used to communicate with and control a modem).

HeaderThe portion of a packet, preceding the actual data, containing source and destination

addresses, error checking and other fields. A header is also the part of an electronic mailmessage that precedes the body of a message and contains, among other things, the

message originator, date and time.

High KeyA light image that is intentionally lacking in shadow detail.

HighlightThe lightest tones in an image. A spectral highlight is a bright, reflected light source.

HistogramA chart displaying the tonal ranges present in an image as a series of vertical bars.

Home PageThe document that is displayed when you first open a web client program. Also,commonly used to refer to the first document you come to in a collection of documents

on a Web site.


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HostThe main computer system to which users are connected.

HostnameName which officially identifies each computer attached to the Internet.

Hotlist

A file containing lists of Internet Web pages, enabling you to easily access your favoriteWeb pages.

HPHewlett Packard.

HTMLHyperText Markup Language. A system for tagging various parts of a Web documentthat tells the Web client programs how to display the document's text, links, graphics and

attached media.

HueThe color of an object perceived by the eye due to the fact that a single or pair of RGBprimary colors predominates.

HypermediaDescribes hypertext in which various types of data can be stored - sound, images, video

and so on - as regular text.

HypertextA text-linking strategy that lets you jump between related information in a document byclicking on a button or highlighted word. On-line help systems often use hypertext links,

as do some programs designed for the electronic distribution of documents.

I or Return to Quick Index

I/O Input/Output.

I-beamThe blinking vertical line that shows the point at which text or graphics will be inserted.

IBMInternational Business Machines Corporation.

IconA graphic symbol, usually representing a file, folder, disk or tool.

Image MapA graphic divided into regions or "hotspots". When a particular region is clicked, it callsup a web page that has been associated with that particular region.

ImagesetterA device used to record digital data (images and text) onto monochrome film or offsetlitho printing plates by means of a single or multiple intermittent light beams. Color

separated data is recorded as a series of slightly overlapping spots to produce either solidareas of line-art or halftone dots for printing continuous tones.

ImportTo bring data into a document from another document, often generated by a different

application.


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Inactive WindowA window that is open but is not the top window.

InfopathInternet gopher for the University of California at San Diego.

Information Technology

Includes matters concerned with the furtherance of computer science and technology,design, development, installation and implementation of information systems andapplications.

Initializing (formatting)Setting up a disk (any kind) to receive information. When a disk is initialized (formatted),

its magnetic media is divided into tracks and sectors, and structure files that yourcomputer uses to keep track of data are created.

Inline imagesGraphics that are contained within a document's textual information. In a Web document,

these graphics can either be loaded automatically when the page is accessed or loadedmanually by clicking on the image's icon.

InstallerA utility that copies system software or an application from floppy disks or a CD-ROM

to your hard disk. An Installer may also decompress the new files, remove obsolete files,place extensions and control panels in their proper folders, and/or create new folders.

InterfaceThe way a computer interacts with a user or a peripheral.

InternetThe Internet (note the capital I) is the largest internet in the world. It is a three level

hierarchy composed of backbone networks (e.g., NSFNET, MILNET), mid-levelnetworks, and stub networks. The Internet is a multiprotocol internet.

InterpolationIn the image manipulation context, this is the increase of image resolution by the addition

of new pixels throughout the image, the colors of which are based on neighboring pixels.

InterruptA brief interruption of the computer's activity so that an urgent task can be performed.

IPInternet Protocol is the standard that allows dissimilar hosts to connect to each otherthrough the Internet. This protocol defines the IP datagram as the basic unit of

information sent over the Internet. The IP datagram consists of an IP header followed bya message.

IP AddressNetwork addresses are usually of two types: (1) the physical or hardware address of a

network interface card; for Ethernet this 48-bit address might be 0260.8C00.7666. Thehardware address is used to forward packets within a physical network. (2) The logical or

IP Address is used to facilitate moving data between physical networks and is made up ofa network number, a subnetwork number, and a host number. All Internet addresses at

SDSU have a network number of 130.191, a subnet number in the range of 1-254, and ahost number in the range of 1-254.

IP Datagram


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The basic unit of information passed across the Internet. An IP Datagram is to theInternet as a hardware packet is to a physical network. It contains a source and

destination address along with data. Large messages are broken down into a sequence ofIP Datagrams.

IRC

Internet Relay Chat. A program that allows you to carry on "live" conversations withpeople all over the world by typing messages back and forth across the Internet.

ISAACInformation System for Advanced Academic Computing. Serves as a clearinghouse forinformation about the use of IBM-compatible hardware and software as aids to

instruction and research in higher education. Membership is free to all students, faculty,and staff at these institutions.

ISOInternational Organization for Standardization, the group that developed the OSI

protocols.

ISP

Internet Service Provider. A company that provides access to the Internet. A serviceprovider can offer simple dial-up access, SLIP/PPP access, or a dedicated line.

IT8Industry standard color reference target used to calibrate input and output devices.

ITVInteractive Television.

J or Return to Quick Index

JaggiesSee aliasing.

JavaAn object-oriented programming language to create executable content (i.e. self-running

applications) that can be easily distributed through networks like the Web.

JPEGJoint Photographic Experts Group is a graphic file format that has a sophisticatedtechnique for compressing full-color bit mapped graphics, such as photographs.

K or Return to Quick Index

KBKiloByte. A unit of data storage size which represents 10^3 (one thousand) characters ofinformation.

KbKilobit. 10^3 bits of information (usually used to express a data transfer rate; as in, 1

Kilobit/second = 1Kbps = 1Kb).

Kermit


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An error-checking file-transfer protocol used to copy files from one computer to another.Also the name given to the public domain software distributed by Columbia University,

which supports this protocol.

Kernel SizeThe number of pixels sampled as a unit during image manipulation and sharpening

processes.KeyboardDevice used to manually insert text into the computer. It usually consists of all the letters

of the alphabet, a numbered key pad, F-keys, and various keys for commands.

KeywordSpecified words used in text search engines.

Kilobyte (Kb)1,024 bytes of digital data.

L or Return to Quick Index

LANLocal Area Network. A network of directly-connected machines (located in closeproximity), providing high speed communication over physical media such as fiber

optics, coaxial cable, or twisted pair wiring.

Laser PrinterAlthough a number of devices employ laser technology to print images, this normallyrefers to black-and-white desktop printers, which use the dry toner, xerographic printing

process.

LaserdiscA 12-inch disk that's similar to an audio CD but holds visual images (such as high-qualitymovies) as well as music. Also called a videodisc.

LinksSynonymous with anchors, hotlinks and hyperlinks.

Line ArtImages containing only black and white pixels. Also known as bilevel images. The term

line art is sometimes used to describe drawings containing flat colors without tonalvariation.

LIONLibrary Internet Online Network. A menued front-end system at SDSU that allows access

to a number of databases such as library on-line catalogs, periodical indexes, and Internetgophers.

LISTSERVA distribution list management package whose primary function is to operate mailinglists. It allows groups of computer users with a common interest to communicate among

themselves.

Local system

The system you are using. Interactions between your computer and another computer onthe Internet are sometimes described using the terms "local" and "remote" systems. The

local system is your computer and the remote system is the other computer.


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LOCISLibrary of Congress catalog system. The Library of Congress has an extensive and useful

congressional legislation system that you can use to look up the bills that are in Congress,as well as having nearly any book ever published in the United States.

Login

The account name used to access a computer system.LossyImage compression that functions by removing minor tonal and/or color variations,

causing visible loss of detail at high compression ratios.

Low KeyA dark image that is intentionally lacking in highlight detail.

LPI/LPCMLines per inch or per centimeter. Units of measurement for screen ruling.

LurkerSlang term for someone who regularly reads newsgroup, BBS, or mailing list discussions,but rarely participates in them.

Lynx A type of browser designed to work with text-only Internet connections like dial-up

UNIX shell accounts.

LZWThe Lempel-Ziv-Welch image compression technique.

M or Return to Quick Index

Mail MergeThe merging of database information (such as names and addresses) with a lettertemplate in a word processor, in order to create personalized letters.

Mailing ListA list of Email users who are members of a group. A mailing list can be an informal

group of people who share Email with one another, or it can be a more formalLISTSERV group which discusses a specific topic.

MainframeA large, multi-tasking computer that is used by many users.

MarvelMachine-Assisted Realization of the Virtual Electronic Library. The Library of Congress'

gopher. It presents information about the Library of Congress such as facilities andservices, reading rooms, copyright, services to libraries and publishers, etc., as well asother Internet resources.

Math CoprocessorAnother name for a floating-point processor.

MatrixThis often refers to a 2-dimensional array of CCD elements.

MediumThe material used to support the transmission of data. Examples include twisted-pair

wire, coaxial cable, optical fiber, or electromagnetic wave (microwave).


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Megabit (Mb)Megabit. 10^6 bits of information (usually used to express a data transfer rate; as in, 1

Megabit/second = 1Mbps).

Megabyte (MB)MegaByte. A unit of data storage size which represents 10^6 (one million) characters of

information.Megahertz (MHz)A million cycles (occurrences, alterations, pulses) per second. Used to describe the speed

at which a computer's processor (or CPU) operates.

MelvylAn on-line catalog system containing books, music scores and recordings, audiovisualmaterials, maps, and computer files from UC libraries and the California State Library.

Also featured are periodicals from several sources.

MemoryIn general, another word for dynamic RAM, the chips where the computers store systemsoftware, programs, and data you are currently using. Other kinds of computer memory

you may encounter are parameter RAM (PRAM), video RAM (VRAM), and static RAM(SRAM). Most computer memory is volatile, that is, its contents are lost when the

computer shuts down.

MenuA list of commands.

Menu BarThe horizontal bar that contains the names of available menus. The menu bar is locatedbelow the title bar.

MessageA collection of data that is ordered according to the rules of a given protocol suite, such

that it is intelligible to the sending and receiving software.

MHzMegahertz. A million cycles (occurrences, alterations, pulses) per second. Used todescribe the speed at which a computer's processor (or CPU) operates. A 25-MHz

processor can handle 25 million operations per second.

MIDIMusical Instrument Digital Interface. A technology that enables a computer to record andplay musical performance.

MidtoneThe middle range of tones in an image.

MILNETMilitary Network. A network used for unclassified military production applications. It is

part of the DDN and the Internet.

MIMEMulti-purpose Internet Mail Extensions. A format originally developed for attachingsounds, images and other media files to electronic mail, but now also used with World

Wide Web applications.

MIME mappings

A list of file extensions and the types of files they belong to. When the server sends anHTTP reply, it sends a type/subtype header according to the requested file's extension.


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MIME type/subtypeAn HTTP header sent with a reply that determines how a client will view or use the

message. The MIME type tells the general type of document, such as image orapplication, and the subtype tells the specific type such as GIF or ZIP.

MIPS

Millions of Instructions Per Second.Mirror siteAn FTP site that is created after the contents of an original FTP archive server are copied

to it. Usually, mirror sites use larger and faster systems than the original, so it's easier toobtain material from the mirror. Mirror sites are usually updated daily, so everything on

the original is also at the mirrors. Tip - Always use the mirror site that is physicallyclosest to you.

ModemA device that, once connected to a telephone line, will enable you to link to the internet

or to other computers.

Moire

A repetitive interference pattern caused by overlapping symmetrical grids of dots or lineshaving differing pitch or angle.

MonitorThe viewing device connected to a computer. Like a TV it displays what you are doing

on the computer, usually in color. The size of the monitor is determined by measuringdiagonally from corner to corner.

MonochromeSingle-colored. An image or medium displaying only black-and-white or greyscale

information. Greyscale information displayed in one color is also monochrome.

MotherboardThe heart, soul, and brains of a computer. This plastic board resembles a miniature city,but its buildings are actually chips for things like the processing, RAM, and ROM, and

the tiny roads connecting them are circuit traces. Also called the logic board. There areno fatherboards or sonboards, but see daughterboard.

MottlingA texture similar to orange peel sometimes caused by sharpening. It is particularly visible

in flat areas such as sky or skin.

MouseA device used to navigate around the computer screen and input information by means ofpointing and clicking.

MOVA file extension found on the World Wide Web that denotes that the file is a movie or

video in QuickTime format.

MPEGMoving Pictures Expert Group. MPEG is an international standard for video compressionand desktop movie presentation. You need a special viewing application to run the

MPEG movies on your computer. MPEG II is a newer standard for broadcast-qualityvideo.

Multimedia


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Any presentation or software program that combines several media, such as graphics,sound, video, animation, and/or text.

MultiplexThe division of a single transmission medium into multiple logical channels supporting

many apparently simultaneous sessions.

MultitaskingThe capability of an operating system to handle multiple processing tasks, apparently, atthe same time. For example: Running 2 or more software programs at the same

time. This would allow you to work between the two or more applications at the sametime.

N or Return to Quick Index

NativeSoftware that's written specifically to run on a particular processor. For example, a

program optimized for a 68K processor runs in native mode on a Quadra, but it runs inemulation mode (which is slower on a Power PC-based Power Mac). Also, the file format

in which an application normally saves it documents. The native format is generallyreadable only by that application (other programs can sometimes translate it using filters).

Navigation ToolsAllows users to find their way around a website or multimedia presentation. They can be

hypertext links, clickable buttons, icons, or image maps.

NetiquetteA form of online etiquette. This term refers to an informal code of conduct that governswhat is generally considered to be the acceptable way for users to interact with one

another online.

news A term often used to denote USENET news, a popular forum for discussion on theInternet.

newsgroupA discussion group, usually found on USENET news. Each group devotes its discussions

to a specific topic.

newsreaderA software program that lets you subscribe to newsgroups as well as read and postmessages to them.

news serverA machine that contains a number of USENET newsgroups. Also referred to a NNTPserver.

NetwareThe chief priest of network operating systems.

NetworkIn general, a group of computers set up to communicate with one another. Your network

can be a small system that's physically connected by cables (a LAN), or you can connectseparate networks together to form larger networks (called WANs). The Internet, for

example, is made up of thousands of individual networks.


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NFSNetwork File System. A protocol developed by Sun Microsystems which allows a

computer system to access files over a network as if they were on its local disks. Thisprotocol has been incorporated in products by more than two hundred companies, and is

now a de facto Internet standard.

NIC Network Information Center. A organization that provides information, assistance andservices to network users.

NOCNetwork Operations Center. A location from which the operation of a network or internet

is monitored. Additionally, this center usually serves as a clearinghouse for connectivityproblems and efforts to resolve those problems.

NodeA computer that is attached to a network; sometimes called a host.

NoiseIn the scanning context, this refers to random, incorrectly read pixel values, normally due

to electrical interference or device instability.Non-lossyImage compression without loss of quality.

NSFNETNational Science Foundation Network. The NSFNET is a high speed network ofnetworks which is hierarchical in nature. At the highest level is a backbone network

which spans the continental United States. Attached to that are mid-level networks andattached to the mid-levels are campus and local networks. NSFNET also has connections

out of the U.S. to Canada, Mexico, Europe, and the Pacific Rim. The NSFNET is part ofthe Internet.

O or Return to Quick Index

Object-orientedGenerally used to describe an illustration or font file as being created by mathematical

equations. Also see Bit-map.

OCROptical Character Recognition. A technology that lets you scan a printed page (with ascanner) and convert it into text document that you can edit in a word processor.

Offset lithographyA high-volume, ink-based printing process, in which ink adhering to image areas of alithographic plate is transferred (offset) to a blanket cylinder before being applied to

paper or other substrate.

On-lineActively connected to other computers or devices. You're on-line when you've logged onto a network, BBS, or on-line service. A device such as a printer is on-line when it's

turned on and accessible to a computer. If you're not on-line then you're off-line.

On-line Service


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A commercial service that (for a price) provides goodies such as e-mail, discussionforums, tech support, software libraries, news, weather reports, stock prices, plane

reservations, even electronic shopping malls. To access one, you need a modem. Popularon-line services include America Online, CompuServe, and Prodigy.

Operating System

Software that supervises and controls tasks on a computer.Optical ResolutionIn the scanning context, this refers to the number of truly separate readings taken from an

original within a given distance, as opposed to the subsequent increase in resolution (butnot detail) created by software interpolation.

Optical Video DiscCompact discs which use lights to read information.

OSIOpen Systems Interconnection, a set of standard protocol grouped into seven layers: the

physical, data link, network, transport, session, presentation, and application layers.

P or Return to Quick Index

PACPublic Access Catalog. The SDSU University Library's on-line catalog which lists thebooks held here and the journals subscribed to (but not their contents. It also provides

information on circulation status, books and journals ordered but not yet received, receiptof journal issues, and more.

PacketThe unit of data sent across a packet switching network. While some Internet literature

use the term to refer specifically to data sent across a physical network, other literatureviews the Internet as a packet switching network and describes IP Datagrams as packets.

Packet-switchingData transmission process, utilizing addressed packets, whereby a channel is occupied

only for the duration of the packet transmission. SDSUnet is a are packet-switchingnetwork.

PaintThe oldest and most limited Macintosh graphic file format, holding only black-and-white

bit maps at 72 dpi. Paint files (file type PNTG) are limited to 8 by 10 inches.

Parallel Cable/Parallel PortA cable used to connect peripheral devices through a computer's parallel port. A type ofport that transmits data in parallel (several bits side by side).

ParameterA word, number, or symbol that is typed after a command to further specify how thecommand should function.

ParityA check bit used to make the sum of the bits in a unit of data either even or odd

(including the parity bit). A unit of data that is 8 bits long would have no parity, and aunit of data 7 bits long would have an even parity bit to make an 8 bit word. Parity is


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used to check a unit of data for errors during transmission through phone lines or nullmodem cables.

PasteTo insert information from the Clipboard. Information can be pasted multiple times.

Path

A route used in finding, retrieving, and storing files on a disk. The course leading fromthe root directory of a drive to a particular file.

PERL

The Practical Extraction and Report Language. An interpreted language for CGI scripts.

PCMCIAA standard format for credit-card-size expansion cards, used to add features to laptopcomputers, hand-held computers, and desktop computers. The acronym stands for

Personal Computer Memory Card International Association.

PDFPortable Document Format. A PDF file is an electronic facsimile of a printed document.

Peer-to-peer

A network setup that allows every computer to both offer and access network resources,such as shared files, without requiring a centralized file server. Macintosh computers

utilize this type of network setup.

PeripheralA piece of hardware that's outside the main computer. It usually refers to externalhardware such as disk drives, printers, and scanners sold by a third party.

PERLPractical Extraction and Reporting Language. A robust programming language frequently

used for creating CGI programs on web servers.

PICSThe standard macintosh graphic file format for animations. Essentially a collection of bit-mapped PICT images in sequential order, much like movie frames.

PICT/PICT 2PICT is the standard macintosh graphic file format for graphics that are cut or copied to

the Clipboard and for drawings that won't be output on PostScript printers. This format isideal for on-screen presentations, but page layout programs sometimes have problems

with PICT files. Files are sometimes called metafiles because they can contain both bitmaps and QuickDraw-based objects.

PixelPicture element. Digital images are composed of touching pixels, each having a specific

color or tone. The eye merges differently colored pixels into continuous tones.

Pixel SkippingA means of reducing image resolution by simply deleting pixels throughout the image.

PKZIP/PKUNZIPA software compression utility for the PC. It allows you to compress or "zip" a file or anumber of files into one archive file in the ZIP file format.

Plug-InExtends the capabilities of a web browser, allowing the browser to run multimedia files.

PMTPhotomultiplier tube. The light sensing device generally used in drum scanners.


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POPA server using the Post Office Protocol, which holds users' incoming e-mail until they

read or download it.

Port

One of several rendezvous points where TCP/IP connections can be made on a computer.

Ports are numbered, with several locations reserved for specific types of network activity,such as telnet on port 23, HTTP traffic on port 80 and USENET news (NNTP) on port119.

PosterizationThe conversion of continuous tone data into a series of visible tonal steps or bands.

ppi/ppcPixels per inch or pixels per centimeter. Units of measurement for scanned images.

PPPPoint-to-Point Protocol. It provides a method for transmitting packets over serial point-to-

point links.

PRAM

Parameter RAM (pronounced pee-ram). A small portion of the Mac's RAM set aside tohold basic information such as the date and time, speaker volume, desktop pattern, and

key-board and mouse settings. PRAM is powered by a battery, so it doesn't lose thesettings when you shut down. Sometimes, however, the PRAM data gets corrupted,

causing crashes or other problems.

Primary colorA base color that is used to compose the other colors.

PrinterA device that transfers information you create on the computer into a printed (paper)form. Most printers will output both black and white and color pages.

Process Ink ColorsCMYK pigments used in printing processes, chosen to produce the widest range of color

mixtures.

ProfileThe color characteristics of an input or output device, used by a CMS to ensure colorfidelity.

PropertiesInformation about an object, including settings or options for that object. For example,

you look at properties of a file for information such as the file size, file type, and fileattributes.

ProtocolsWhen data is being transmitted between two or more devices something needs to govern

the controls that keep this data intact. A formal description of message formats and therules two computers must follow to exchange those messages. Protocols can describe

low-level details of machine-to-machine interfaces (e.g., the order in which bits and bytesare sent across wire) or high-level exchanges between application programs (e.g., the

way in which two programs transfer a file across the Internet).

Proxy ARPA technique in which one machine, usually a gateway, answers ARP requests for anothermachine. By pretending to be the physical network location of another machine, the


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gateway takes over the responsibility of routing packets destined for the other machine.For instance, a gateway can proxy ARP for addresses that the gateway identifies as being

off the local network and that the gateway has a route for. The originating computerreceives the gateway's proxy ARP reply and sends the datagram on to the gateway, which

routes the datagram to its actual destination network.

PSN Packet Switch Node; a store-and-forward packet switch (formerly called an IMP).

Public-domainSoftware that has no copyright or fee, which means you can copy, use, and even alter andsell it.

Q or Return to Quick Index

Quality FactorA multiplication factor (between 1 and 2) applied to output screen ruling to calculate

scanning resolution for optimum output quality. This is also known as the halftoningfactor.

Quarter TonesTones between shadow and midtones are known as 3/4 tones and those between highlight

and midtones are known as 1/4 tones.

QueryThe process by which a web client requests specific information from a web server, basedon a character string that is passed along.

QuickTimeA file extension for videos or "movies" (like animations) compressed using their

QuickTime format.

R or Return to Quick Index

RAMRandom Access Memory. RAM is the most common type of computer memory, and it's

where the computer stores system software, programs, and data you are currently using.It's formally called dynamic RAM (DRAM) because it's volatile, that is, the contents are

lost when you turn off the computer (or crash). It's pronounced ram and measured inmegabytes.

RasterA synonym for grid. Sometimes used to refer to the grid of addressable positions in an

output device.

RelRecorder element. The minimum distance between two recorded points (spots) in animagesetter.

Remote system


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Another computer on the Internet to which you connect. Interactions between computersare often described using the terms "local" and "remote" systems. The local system is

your computer and the remote system is the other computer.

ResA term used to define image resolution instead of ppi. Res 12 indicates 12 pixels per

millimeter.ResamplingAn increase or reduction in the number of pixels in an imge, required to change its

resolution without altering its size. See also down-sampling and interpolation.

ResolutionIn general, this refers to how sharp and clear an image looks on screen or on paper, andhow much detail you can see. It's usually determined by the number of dots (or pixels)

per square inch (the more there are, the higher the resolution) and is used to describeprinters, monitors, and scanners.

RFCRequest For Comments; technical note series which began in 1969 describing DARPA

and Internet research and development, particularly in the areas of protocol design andinternetworking. Not all (in fact very few) RFCs describe Internet standards, but all

Internet standards are written up as RFCs.

RGBRed, green, and blue are the primary colors of light perceived by the eye.

RIPRouting Information Protocol used by Berkeley UNIX systems to exchange routinginformation among a set of computers attached to a network. RIP packets are sent and

received by a program called routed.

ROGEROn-line catalog at UCSD for books and other material in the libraries at the University ofCalifornia at San Diego.

ROMRead-Only Memory. It's like software that's hard-wired into your computer - basic,

permanent information that tells it things like how to load up the operating system whenyou turn it on.

RouterA special purpose computer that attaches to two or more networks and routes packets

from one network to the other. A router uses network layer addresses (such as IPAddresses) to determine if packets should be sent from one network to another. Routers

send packets to other routers until they arrive at their final destination.

rpiRels (recorder elements) per inch. A measurement of the number of discrete steps thatexposure units in imagesetting devices can make per inch.

RS-232Interface between Data Terminal Equipment (DTE) and Data Communications

Equipment (DCE) employing Serial Binary Data Interchange, a standard set by theinternational standards organization - Consultative Committee on International

Telegraphy and Telephony. The interface between a terminal to a modem for the transferof serial data.


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RTFRich Text Format. A file format for text files that includes formatting instructions. Also

called Interchange Format.

S or Return to Quick Index

SamplingThe process of converting analog data into digital data by taking a series of samples orreadings at equal time intervals.

SaturationThe extent to which one or two of the three RGB primaries predominate in a color. As

quantities of RGB equalize, color becomes desaturated towards grey or white.

ScannerA device that converts printed images (such as photographs or text) into digital form sothat they can be stored and manipulated on computers.

Screen FrequencyThe number of rows or lines of dots in a halftone image within a given distance, normally

stated in lines per inch (lpi) or lines per centimeter (lpm). A frequency of 200 lpi wouldonly be used in high-quality printing.

Screen RulingAnother term used for screen frequency.

Screen SaverA moving picture or pattern that is displayed on the screen when no activity takes place

for a specified period of time.

ScriptsA type of program that consists of a set of instructions for another application or utility touse.

Scroll BarThe bar that appears at the right side or the bottom of a window that contains more

information that can be displayed. The scroll bar is used to scroll an object or parts of adocument into view when the entire object or document does not fit in the window.

SDSUnetSan Diego State University Network. The backbone network that connects multiple

buildings on the SDSU campus.

Search EnginesA type of software that creates indexes of databases or Internet sites based on the titles offiles, key words, or the full text of files.

Second OriginalHigh-quality, contone reproduction of an image, intended to be identical to the original.

Secondary ColorColor obtained by mixing two primary colors. Although known as primary colorants,C,M, and Y are the secondary colors of light. Red plus green produce yellow, for

example.

Serial Cable/Serial Port


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A cable used to connect peripheral devices through a computer's serial port. Normally a25-pin connector on each end, yet can be a 9-pin on one. A Serial Port can either be

plugged into an expansion slot on the motherboard of your computer or built into themotherboard itself. Serial ports are used for such devices as printers, mice, and modems.

Server

A computer that shares its resources, such as printers and files, with other computers onthe network. An example of this is a Novell NetWare Server which shares its disk spacewith a workstation that does not have a disk drive of its own.

Service (NT service)A process that performs a specific function in Windows NT and can be called by various

other programs. Windows NT provides tools to monitor and administer services.

ShadowThe darkest area of an image.

SharewareSoftware that you can try before you buy. It's distributed through on-line services, BBSs,and user groups. You're allowed to try it out and give copies to others, but if you want to

keep using it, you must pay the registration fee.ShockwaveA set of programs that allow Macromedia Director animation files to be played over theinternet with a web browser.

SiteOrganization or facility where a host is located.

Site-licenseThrough negotiations with a vendor, a renewable fee has been paid to allow a fixed

number of copies of copyrighted software at one site.

SLIPSerial Line Internet Protocol. A protocol used to run IP over serial lines, such astelephone circuits or RS-232 cables, interconnecting two systems.

SMTPSimple Mail Transfer Protocol. Internet standard protocol for transferring electronic mail

messages from one computer to another. SMTP specifies how two mail systems interactand the format of control messages they exchange to transfer mail.

SocketLogical address of a communications access point to a specific device or program on a

host.

SoftwareThe actual programs that make the computer operate. For instance; word processing,graphic arts, spreadsheets and device drivers.

SPAMRefers to the practice of blindly posting commercial messages or advertisements to a

large number of unrelated and uninterested newsgroups.

SpecklingIsolated light pixels in predominantly dark image areas, sometimes caused by incorrectreadings or noise in the scanning device.

Spectral HighlightA bright reflection from a light source containing little or no detail.


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SpectrophotometerAn extremely accurate color measurement device using a diffraction grating to split light

into its components wavelengths, which are then measured by numerous light sensors.

SpreadsheetA number-related document whereby calculations and formulas are applied to the data

organized in rows and columns of cells.SQLStructured Query Language, a syntax used by many database systems to retrieve and

modify information.

StaircasingSee Aliasing.

Start/Stop BitsA start bit signals the start of a unit of data in asynchronous communications. A stop bitsignals the stop of a unit of data. The unit can vary in length depending on the protocol.

Subnet AddressAn extension of the Internet addressing system that allows a site to subdivide a single

Internet address to cover multiple physical networks. This is done by dividing up the hostaddress part of an IP Address into a local network number and host address number.

SubstrateThe base material used to carry out or support an image, for example, paper or film.

Subtractive PrimariesAnother term for primary colorants.

SupersamplingThe capture of more grey levels per color than is required for image manipulation or

output. This additional data allows shadow details to be heightened, for example.

Syntax ErrorOccurs when a user (or programmer) has put words in an order that a program does notunderstand.

T or Return to Quick Index

T1An AT&T term for a digital carrier facility used to transmit a DS-1 formatted digital

signal at 1.544 megabits per second.

T3A term for a digital carrier facility used to transmit

TagsFormatting codes used in HTML documents. These tags indicate how the parts of a

document will appear when displayed by a Web client program.

Taskbar

An area that runs across the bottom (usually) of the Windows 95 desktop. Runningapplications are represented as buttons on the taskbar, the current window is shown as a

depressed button, all other applications are displayed as raised buttons.

TCP


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Transmission Control Protocol. This is a transport layer protocol that establishes areliable, full duplex, data delivery service used by many TCP/IP application programs.

The TCP software uses the IP protocol to transmit information across the Internet.

TCP/IPTransmission Control Protocol/Internet Protocol. A set of protocols, resulting from

ARPA efforts, used by the Internet to support services such as remote login (TELNET),file transfer(FTP) and mail (SMTP).

TELNETThe Internet standard protocol for remote login (terminal connection) service. TELNETallows a user at one site to interact with a remote timesharing system at another site as if

the user's terminal were connected directly to the remote computer.

TerminalCommunication device that lets a user send information to a computer by typing on akeyboard, and prints responses from the computer on paper or a screen.

Terminal ModeMany communications programs allow you to mimic a computer terminal, which is

basically a keyboard and CRT display and/or a printer. A common terminal modeemulator is VT-100.

Terminal Ready (TR)This light is illuminated when your computer has turned on the RS-232 (serial)

interface. Sometimes this light will not come on until you have loaded yourcommunications software into memory.

Terminal ServerA small, specialized, networked computer that connects many terminals to a LAN

through one network connection. A terminal server can also connect network users toasynchronous ports or a host.

Thermal Wax TransferA printing process using small heating elements to melt dots of wax pigment on a carrier

film, which are then transferred to paper or transparent film by contact. This differs fromthe dye sublimation process in that individual dots do not fuse together, so thermal wax

transfer appears to be of a lower resolution.

ThreadIn the context of Windows NT, a thread is sometimes used to refer to an NT service.Threading also refers to a low-level system architecture concept used in some

multitasking operating systems.

ThresholdThe point at which an action begins or changes. The threshold setting used in scanningline art determines which pixels are converted to black and which will become white. The

threshold defined in the USM process determines how large a tonal contrast must bebefore sharpening will be applied to it.

TIFFTag Image File Format. A graphic file format, TIFF files are also bit maps, but they can

be any size, resolution, or color depth. It is the most versatile, reliable, and widelysupported bit-mapped format and is the standard format for saving scanned images.

However, the format does have several variations which means that occasionally anapplication may have trouble opening a TIFF file created by another program.


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Title barThe horizontal bar at the top of a window. The title bar shows the name of the window.

Tone CurvesAlso known as gamma curves. These are used to smoothly adjust the overall tonal range

of an image, or the individual tonal ranges of each color channel.

ToolbarA collection of buttons that typically make the more common tools for an applicationeasily accessible.

TSRTerminate and Stay Resident.

U or Return to Quick Index

USMUnsharp masking. A process used to sharpen images.

UUCPUNIX-to-UNIX Copy Program. This was initially a program run under the UNIX

operating system that allowed one UNIX system to send files to another UNIX systemvia dial-up phone lines. Today, the term is more commonly used to describe the large

international network which uses the UUCP protocol to pass news and electronic mail.

UncoverA database of book reviews, magazines, and articles, including FAX article delivery. Itprovides table of contents information for over 14,000 journals in all disciplines held by

the libraries in the Colorado Academic and Research Libraries consortium and provideson-line access to ERIC, at education database. Coverage for most journals begins with

1989.

UNICOSA version of the UNIX operating system adapted for CRAY computers.

UNIX

An operating system developed by Bell Laboratories that supports multiuser andmultitasking operations.

UploadSend a file to another computer using a modem.

UPSUninterruptible Power Supply. A unit that switches to battery power whenever the power

cuts out.

URIUniform Resource Identifier, a string of characters that represents the location or addressof a resource on the Internet and how that resource should be accessed. A URI is a

superset of the Uniform Resource Locator.

URL


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Uniform Resource Locator, a string of characters that represents the location or addressof a resource on the Internet and how that resource should be accessed. World Wide Web

pages are assigned a unique URL. Each hyperlink on a web page contains the URL of thepage to be linked to. http://rohan.sdsu.edu/glossary.html is the URL for this page.

USENET

A network of newsgroups. There are thousands of newsgroups available throughUSENET. Each one covers a specific topic or subject area.

User IdThe string of characters that identifies you. The name by which you are known to thenetwork. Also known as username.

UUCPUNIX-to-UNIX Copy Program, a program that lets you copy files between UNIX

systems. UUCP protocols are used to transfer news and Email messages throughUSENET.

V or Return to Quick Index

VeronicaVery East Rodent-Oriented Net-wide Index to Computerized Archies. An index searcher

of Gopher repositories. Searches are based on keyword criteria to help users find Gopher-based information without doing a menu-by-menu, site-by-site search.

VideodiscA 12-inch disk that's similar to an audio CD but holds visual images (such as high-quality

movies) as well as music. Also called a laserdisc.

VirusA program that replicates itself from one file or disk to another without your consent.They are spread through floppy disks, networks, and on-line services and can go

undetected (unless you have an antiviral utility) until something goes wrong. Someviruses deliberately destroy data, and even those designed to be benign can cause

crashes, slowdowns, and file corruption.

VMSDigital Equipment Corporation proprietary operating system which runs on the VAXseries of machines.

VODVideo On Demand.

VRAMVideo RAM. A type of memory dedicated to handling the image displayed on a monitor.VRAM is built into many Macs, and it also comes on display cards.

W or Return to Quick Index

WAIS


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Wide Area Information Server. WAIS is best at searches for various sources of academicinformation that has been indexed based on content. Its indexes consist of every word in a

document and each word carries the same weight in a search.

Wallpaper

A graphical pattern displayed on the desktop.

Web browserAlso known as a Web client program, this software allows you to access and view HTMLdocuments. Netscape, Mosaic, Lynx, WinWeb, and MacWeb are some examples of Web

browsers.

Web pageA document created with HTML that is part of a group of hypertext documents orresources available on the World Wide Web.

Web walkingUsing a Web client program to move through the documents available on the World

Wide Web. This casual browsing nature of navigating the WWW has also been referredto as strolling, crawling and jumping.

WebmasterA person or group of people who maintain and administer a web server. Webmaster also

refers to a standard Email address at most web hosts where comments and questions canbe sent.

White PointA movable reference point that defines the lightest area in an image, causing all other

areas to be adjusted accordingly.

WHOIS

An Internet program which allows users to query databases of people and other Internetentities, such as domains, networks, and hosts. The information for people generally

shows a person's company name, address, phone number and email address.

Wide Area Network (WAN)

Network spanning multiple geographic distances, usually connected by telephone lines,microwave, or satellite links.

WildcardA character (usually * or ?) that can stand for one or more unknown characters during a

search.

Windows

Microsoft software that adds a Mac-like graphical user interface to IBM PCs andcompatibles.

Word ProcessingEntering, editing and formatting text with the use of spelling checkers, outlining, tables,

footnotes, and tables of contents.

Workstation

A networked personal computing device with more power than a standard IBM PC orMacintosh. Typically, a workstation has an operating system such as UNIX that is

capable of running several tasks at the same time. It has several megabytes of memoryand a large high-resolution display.

WWW


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World Wide Web or W3 is the hypermedia document presentation system that can beaccessed over the Internet using software called a Web browser.

WYSIWYGWhat you see is what you get. The image you see on the screen matches what will print

on paper. Pronounced wizzy-wig.

X or Return to Quick Index

X.25A data communications interface specification developed to describe how data passesinto and out of public data communications networks. The CCITT and ISO approved

protocol suite defines protocol layers 1 through 3.

Z or Return to Quick Index

ZipA way of compressing a program or documents onto a small storage media.

Return to Quick Index

technology terminology 091

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