| Technical Glossary The Journey InsideSM uses a contextual glossary. Clicking on an underlined word in the lessons, the readings, or the activities opens a pop-up window with the word's definition. The glossary below includes all the underlined terms. A B C D E F G H I J K L M N O P Q R S T U V W X Y Z A AC power adapter Converts alternating current to direct current. Acrobat Reader* Document exchange software from Adobe Systems, Inc. Adobe Acrobat* provides a platform-independent means of creating, viewing, and printing documents. Acrobat can convert a DOS, Windows*, UNIX* or Macintosh* document into a portable document format (PDF), which can be displayed on any computer with Acrobat Reader*. Acrobat Reader can be downloaded* free from the Internet. adapter (converter) A device that is used to convert current from one form to another form. address book, email A small database in which you store email addresses for the individuals and groups that you correspond with, each labeled with an easy-to-remember nickname that you assign. address, Internet See Internet IP address. alternating current (AC) Current that changes direction on a regular time interval. American Standard Code for Information Interchange (ASCII) (Pronounced ass-key). An agreed method for pairing the alphanumeric character set with binary representations used in computers. ampere The unit used to measure current. One ampere is 6.28 x 1018 electrons passing a specific point in one second. application A program that helps the user accomplish a specific task; for example, a word processing program, a spreadsheet program, or a file transfer protocol client. Application programs are distinguished from system programs (which control the computer and run the application programs) and utilities (which are small helper programs). arithmetic logic unit The portion of the microprocessor used for numerical and logical calculations. artificial intelligence A branch of computer science which tries to simulate aspects of human intelligence, including the ability to learn from experience and to use reason to solve a problem or respond to a new situation. atom The smallest particle of an element that can combine with similar particles of other elements to form the molecule of a compound. Atoms commonly consist of electrons (negatively charged particles) revolving around a positively charged nucleus containing protons, neutrons, and other particles. AU A sound file format, originally for Sun UNIX* systems, now also supported on personal computers and Macintoshes. AVI (AudioVideo Interleaved) Microsoft's video for Windows* movie format, used for storing video with audio. B bandwidth The amount of data a cable can carry. baseband network A network that sends data as direct signals, which means only one person can transmit data at any given time. baud A measure of transmission rate in bits-per-second. binary Anything that has only two states such as on/off or yes/no. binary code A coding system that relies on the use of bits—0s and 1s—to encode information. binary digit Either character used in the binary number system, so a 0 or a 1. bit A binary digit, a 0 or a 1. bitmap In bitmap graphics, an image is displayed on the screen as a collection of tiny squares called pixels, which together form a pattern. Each pixel in the image corresponds with one or more bits; the number of bits per pixel determines how many shades of gray or colors can be displayed. BMP A Windows format for a bitmapped graphics file. Boolean In computer science and digital electronics, this term means an expression with two possible values, "true" and "false." The most common Boolean operators are AND, OR, and NOT. bps An abbreviation for bits per second. This is the common measurement used for comparing the speed at which devices such as modems can transfer data. broadband network A type of network that allows transmission of several types of data at the same time. browser A program that allows users to read hypertext documents on the World Wide Web, and navigate between them. Examples are Firefox*, Safari*, and Microsoft Internet Explorer*. Browsers can be text-based or graphic. bug An error in the code of a program or an error in the design of a hardware component. bunny suit Special clothing worn by workers in a clean room that helps to keep human contaminants away from the chips. byte A byte is 8 bits; one byte can represent a single character. On most computers, the byte is the basic unit of addressable memory. On IBM mainframes, a word is 4 bytes (32 bits). C cache A temporary storage area for frequently accessed or recently accessed data. Having certain data stored in a cache speeds up the operation of the computer. There are two kinds of cache: internal (or memory cache) and external (or disk cache). Internal cache is built into the processor, and external cache is on the motherboard. When an item is called for, the computer first checks the internal cache, then the external cache, and finally the slower main storage. capacitor A device used in a circuit to temporarily store electricity. case sensitive Treating upper case letters as different characters from the same letters in lowercase. Filenames or text searches that are case-sensitive would distinguish between, for example, Internet and internet. charge The condition of having an excess or deficiency of electrons. chat acronyms These common acronyms (and dozens more) are used in online, real-time, typed conversation and in email as a form of shorthand communication.
chip An integrated circuit. A thin piece of silicon that contains all the components of an electronic circuit. circuit diagram A representation of the circuit using special symbols for each part placed in the circuit. circuit line A pathway used to move electricity from one component to another, often made of small wires or deposited metals. clean room A room in which dust and other small particles are meticulously filtered from the air to avoid contaminating electronic components during manufacture or testing. Protective clothing is worn by workers to prevent any particles from moving from the worker's body into the room. client A computer that makes requests of other devices in a network or that uses resources available through the servers. clipboard An area of temporary memory which is used to transfer text and graphics within a document being edited, or between documents. The data is put into the clipboard with either the Cut or Copy command, and then the Paste command takes it from the clipboard and puts it in its new location. coaxial cable Networking cable that provides some shielding between the insulation and outside of the cable which helps to prevent interference problems with the signals. conductor A material that in its pure form allows the flow of an electrical charge to pass through it easily. contamination Intrusion or contact with dirt, dust, or impurities that adversely affect chip fabrication. control unit The circuits on the microprocessor that tell the microprocessor to carry out the instructions and control the timing of the instructions. cookie A cookie is a set of data that a Web site server gives to a browser the first time the user visits the site, that is updated with each return visit. The remote server saves the information the cookie contains about the user and the user's browser does the same, as a text file stored in the Netscape or Explorer system folder. CPU (central processing unit) The "brain" of the computer that performs most computing tasks. In microcomputers, the entire CPU is on a single chip. Also called a processor. crop A graphic/photo formatting term: To trim the edges of a graphic image, removing part of the image. current The flow of electrons. D data An item or items of information. Data becomes information when it is conveyed in a context that has meaning to people. data block The amount of information from the message that is contained in one packet. database
To locate and correct the error in a program. decode Translation of information from a code into a form that has meaning to the microprocessor. decode unit The circuits used to translate the instructions into control signals and directions, and holds them in sequence until they are requested by the control unit. desktop
A box on the computer screen that can be used to enter information, set options, or give commands to the computer. The dialog box gives the user choices (such as open file, delete, save) which can be selected by clicking with the mouse. digital information Information that can be expressed in a numerical form. The computer uses the binary number system for this purpose so 0s and 1s are used to express all the information entered into the computer. diode A device that is used to limit the movement of electricity to move in one specific direction. Some diodes are designed to also produce light or to act as a switch in an electrical circuit. direct current (DC) Current that only moves in one direction. directory, folder The place on a disk where you can store files and subdirectories. The organization of directories (or folders) and files and on a hard drive is like the branches of an upside-down tree. The main directory is called the "root directory." disk drive A mechanism that holds, spins, reads, and writes magnetic or optical disks. diskette A small, portable, flexible magnetic disk that was used for data storage on some computers. These disks are known as "floppy" disks (or diskettes) because the disk is flexible and the read/write head is in physical contact with the surface of the disk, in contrast to "hard disks" that are rigid and rely on a small, fixed gap between the disk surface and the heads. domain name The unique name that identifies an Internet site. Domain Names always have 2 or more parts, separated by dots. The part on the left is the most specific, and the part on the right is the most general. A given machine may have more than one Domain Name but a given Domain Name points to only one machine. Other endings continue to be added to meet demand for new site names, such as .ws for "world site." Countries have their own URL endings as well; for example, the United Kingdom is .uk, France is .fr, Korea is .kr, Canada is .ca, Philippines is .ph, Australia is .au, etc. For a list of URL domain names for countries around the world, visit Domain name registries around the world http://www.iana.org/domains/root/db/*
DOS (disk operating system) The term DOS can refer to any operating system, but it is most often used as a shorthand for MS-DOS (Microsoft disk operating system). Originally developed by Microsoft for IBM, MS-DOS was the standard operating system for IBM-compatible personal computers. download To transfer files or data from one computer to another. To download means to receive; to upload means to transmit. drain The post of a transistor that passes the current from the transistor and on through the closed circuit. drive A very fast input/output device that consists of one or more spinning magnetic disks. A moving arm allows direct read or write access to data recorded on the disks. A device that spins disks or tapes in order to read and write data; for example, a hard drive, disk drive, CD-ROM drive, or tape drive. DVD (digital versatile disc or digital video disc) A storage medium which has greater capacity and bandwidth than a CD. DVDs can be used for multimedia and data storage. A DVD has the capacity to store a full-length film with up to 133 minutes of high-quality video in MPEG-2 format, plus audio. E electric charge The potential of electrons or protons to attract each other. electrical current The movement of electrons from one atom to another. electrical load Any component or circuit that consumes power delivered to it by a power source, the action a particular circuit is designed to accomplish. electron Any of the negatively charged particles that form a part of all atoms. electronic Adjective for describing a device or result that is dependent on the action of electrons to work. electronic mail (email) A system whereby a computer user can exchange messages with other computer users (or groups of users) through a communications network. email address An email address has the form "person id" at "domain id." For example, jdoe@intel.com. In this email address, Mr. Doe is identified by his logon id, jdoe, and the company name is identified by its Internet domain name, intel.com. embedded processor A chip designed with a specific set of usable instructions. The user cannot change the instructions an embedded processor was programmed to understand. emoticons Typewritten pictures of facial expressions, used in email and when communicating on the Internet, to indicate emotion. Most often producing an image of a face sideways. They are also called smileys :-) The most common emoticons are:
engineer A person who uses scientific knowledge to solve practical problems etching The removal of selected portions of materials to define layers on computer chips. ethernet A popular network protocol and cabling scheme that allows transmission rates of 10 megabits per second. execute To carry out an instruction after it has been decoded. expansion slot A connector inside a computer designed to allow a user to add printed circuit boards to the motherboard. exponential growth A rate of growth that is calculated by multiplying the present rate by a value equal to that number. extension, filename The portion of a filename following the final point (period) that indicates the kind of data stored in the file. Extensions are usually from one to three letters (for example, .ppt, .doc, .au, .wav). external bus unit The pathway provided to move data to and from the microprocessor. F fab The fabrication plant housing all the various processes needed to support a business dedicated to manufacturing computer chips. fabrication The process of manufacturing a computer chip. FAQ (frequently asked questions) Newsgroups, mailing lists and Internet sites often have a list of the most frequently asked questions about their subject, with answers. Favorites and Bookmarks A feature in most internet browsers that enables the user to record URLs that will be frequently used by adding them to a special menu. They can also be known as Bookmarks. Once the URL is on the list, it is easy to return to that Web page simply by clicking on the link in the list, rather than retyping the entire URL. fetch The portion of the microprocessor dedicated to requesting and receiving instructions. fiber optic cable A high-speed network cable that carries light signals on specially manufactured optical fibers. filament A thin fragile thread of material (often carbon or metal) that produces a light when electrons move through it. file A collection of information stored in any of numerous forms on any of numerous devices. A file may contain programs, data, or text. file size The length of a file, typically measured in kilobytes (K) or megabytes (MB). folder On computer screens for Macintosh and Windows 95 (and above), files can be organized by placing them into folders that look like office file folders. font A text formatting term: A complete assortment of printer characters in a particular type style, typeface, size and orientation. Most fonts include letters, numbers, punctuation and some special symbols. Note that the Roman (normal), italic, bold and bold italic typeface forms of any type style and size are each separate fonts. A font family is a complete set of characters in the same type style, including all sizes and typefaces, such as bold, italic and underline. footer A text formatting term: One or more lines of text that appear at the bottom of every page. freeware Software, often written by enthusiasts, distributed at no charge by users' groups, email, local bulletin boards, Usenet, or other electronic media. Freeware is software that is available free of charge, but is copyrighted by the developer, who retains the right to control its redistribution and to sell it in the future. Freeware is different from free software (or software in the public domain), which has no restrictions on use, modification, or redistribution. FTP (file transfer protocol) A protocol in the Internet suite which allows a user on any computer to get files from another computer, or to send files to another computer. G gate The post of a transistor that receives the current used to turn the switch on, completing the circuit so electricity can flow. gateway Hardware and/or software that connects two different network environments. gauge A linear measurement according to some specific system such as the distance between the rails of a railroad. gesture commands The ability of a device such as a computer to recognize hand signals. GIF (Graphics Interchange Format) A format for pictures that many browsers can display. A color-image transfer protocol developed by CompuServe*, GIF format works best for graphics with contiguous areas of solid color like graphics, clip art, and drawings. GIF is the only file format that allows for animation, transparency effects, or interlacing (the graphic loads gradually with a venetian blind effect). GIF files are widely used on Web pages because they provide good-quality color images in a format that takes up a small amount of space. gigabyte 1024 megabytes, or one billion bytes. Abbreviated GB, Gbyte or G-byte. H hard copy Usually hard copy means paper, but presumably can mean any printed computer output, such as microfilm. hard disk or hard drive The main device that a computer uses to store information. Hard disks are rigid aluminum or glass disks about 3.5 inches in diameter in a personal computer, and smaller in a laptop. They are coated with ferromagnetic material and rotate around a central axle. Data is transferred magnetically by a read/write head. A hard disk drive for a personal computer may contain as many as eight hard disks, rotating around the same axle. hardware The physical parts of the computer system that you can touch and feel such as the keyboard, monitor, and computer case. header
The machine that provides processing capabilities for attached terminals, nodes, or clients. hosting To provide the data space for one or more Web sites. Web hosting businesses provide space to businesses and individuals who don't have the resources or desire to have their own Web server. Web hosting businesses are responsible for maintaining the equipment necessary to keep all the sites they host up and running 24 hours a day, seven days a week. HTML (hypertext markup language) The language used to create Web pages, with hyperlinks and markup for text formatting (heading styles, bold, italic, numbered lists, insertion of images, etc.). HTTP (hypertext transport protocol) The rules by which World Wide Web browsers and servers communicate. This is the protocol most often used to transfer information from Web servers to browsers, which is why Web addresses begin with http://. hub A device that acts as a common termination point for multiple nodes and relays signals along the appropriate paths. This ability is often included with another device. hyperlink A link in an HTML document that leads to another place on the same page, to another page on the same Web site, or to another Web site. A browser usually displays a hyperlink in some distinguishing way, such as a different color, font, or style. hypertext Text that has hyperlinks. When hypertext is viewed with an interactive browser, certain words appear highlighted by underlining or color; clicking on a highlighted link leads to another location with more information about the subject. The term was coined by Ted Nelson around 1965 for a collection of documents (or "nodes") containing cross-references or "links" which, with the aid of an interactive browser program, allow the reader to move easily from one document to another. I icon A small picture on the screen that represents a file or program. impure silicon Silicon that has purposely been mixed with some other material to increase the conducting ability of the material. information processing Capturing, storing, updating, and retrieving data and information. A computer is an information-processing machine. input The data that is entered into a computer. The act of entering data into a computer. insulator A material that does not allow an electrical charge to pass through it. integrated circuit A complete circuit on a chip, built by a chip fabrication process. internal bus unit Circuits that manage the flow of information from one part of the microprocessor to another. internal cache A place on the microprocessor reserved for temporarily storing instructions that might be needed in the near future. internet The connection of many smaller networks to form a large, global wide network. Internet Explorer* Microsoft's World Wide Web browser. Internet IP address A unique number identifying each host machine on the Internet network. Also called the IP address or TCP/IP address. A numeric address such as 123.231.32.2 that the domain name server translates into a domain name. In addition to the Internet address, each machine has an Internet domain style name which usually has the form machine.location.domain or machine.group.location.domain. The term is sometimes used incorrectly to refer to a host's fully qualified domain name. Internet The Internet is a network of networks, linking computers to computers by speaking the same language, called TCP/IP protocol. Each computer runs software to provide or "serve" information and/or to access and view information. The Internet includes a variety of electronic services such as electronic mail (email), Telnet (remote login), FTP (file transfer protocol for downloading or uploading of files), Gopher (an early, text-only method for accessing Internet documents), and the World Wide Web. The Internet was originally developed for the United States military, and then became used for government, academic, and commercial research and communications. ISDN (Integrated Services Digital Network) A standard of networking that allows all data to be transferred in digital form. ISO standards The seven-layer ISO (International Standardization Organization) reference model developed to control how types of computer systems will interconnect. ISP (Internet Service Provider) An ISP is a business that provides a connection to the Internet. Some ISPs are big corporations while others are small local operations. J JPEG (Joint Photographic Experts Group) A format for storing high-quality color and grayscale photographs in bitmap form. JPEG files are most effective for photographic images or images with lots of subtle color and tones. K keyboard A computer input device that uses a set of keys to put data into the computer. L LAN (local area network) A collection of two or more computers that are located within a limited distance of each other and that are connected to each other, directly or indirectly. light emitting diode (LED) A diode that produces light when current is present. link A link in an HTML document that leads to another place on the same page, to another page on the same Web site, or to another Web site. A browser usually displays a hyperlink in some distinguishing way, such as a different color, font, or style. When the user activates the link (by clicking on it with the mouse), the browser displays the target of the link. Text or graphics can be links. See also hyperlink. logical address The address of a client assigned by the system supervisor. M mask A patterned plate or template used to expose selected areas of a wafer's layer to light in the process of fabricating a computer chip. media The physical material (whether it be paper, hard disk, CD-ROM, DVD, or anything similar) used for storing computer-based information. megabyte (MB) Equals 1,048,576 bytes, or 1024 kilobytes. The text of a 600-page paperback book would require about 1 megabyte of ASCII storage. (ASCII is the basis of character sets used in almost all present-day computers.) Abbreviated as MB. megahertz (MHz) A measure of speed, 1 million cycles per second. memory The part of a computer system that is used to run programs. The working space used by the computer to hold the program that is currently running, along with the data it needs, and to run programs and process data. The main memory is built from random access memory (RAM) chips. The amount of memory available determines the size of programs that can be run, and whether more than one program can run at a time. Main memory is temporary, and is lost when the computer is turned off. It is distinguished from more permanent internal read only memory (ROM) which contains the computer's essential programs, and storage (the disks and tapes which are used to store data). In the general sense it can be any device that can hold data in machine-readable format. Also see RAM and ROM. memory management unit The circuits designed to keep track of information that has been processed, reclaim the space when the instructions are done, and help organize the way instructions and data are stored. message identifier Information that is placed at the front of the packet to allow each station in the network to identify the message. microcode The built-in set of instructions used by the microprocessor. microelectronics A branch of electronics that deals with the miniaturization of electronic circuits and components. micron A unit of measure that is one millionth of a meter; synonymous with micrometer. microprocessor The main processing unit of a computer or information processing device; the "brains" of the machine carrying out instructions, performing calculations, and interacting with the components used to operate the computer. The microprocessor handles the fetch, decode, and execute steps of the computer. MIDI (musical instrument digital interface) A sound file format. It is a standard connection for digital control of musical devices. Used for synthesized music. Cannot be used for the human voice or other complex sounds. File size is usually small. modem A device that is able to change information back and forth from digital format to continuous analog format allowing computers to use telephone systems for transmitting data. The modem modulates the digital data of computers into analog signals to send over the telephone lines, then demodulates back into digital signals to be read by the computer on the other end; thus the name "modem" for modulator/demodulator. Moore's Law The hypothesis that says that the complexity (processing speed, capacity, power) of chips doubles every two years. motherboard The main circuit board of a computer housing the microprocessor and providing the means of connecting all the components that make up the computer. Provides a means for adding special control units such as sound boards to the computer via expansion slots or sockets. mouse A computer input device used as a pointing and drawing instrument by selecting specific positions on the monitor display. MPEG (Moving Pictures Experts Group) An ISO (International Standards Organization) group that sets standards for compressing and storing video, audio, and animation in digital form. MPEG files use specific compression-decompression (CODECs) technologies to reduce the size of video files by compressing the inter- and intra-frame time. multimedia Multimedia is communication that uses any combination of different media, and may or may not involve computers. Multimedia may include text, spoken audio, music, sounds, images, animation and video. Multimedia often also includes hyperlinked text and objects. mylar The type of plastic that is used to create floppy disks. N navigate To find one's way around on the World Wide Web by following hypertext links from document to document, and from computer to computer. netiquette A pun on "etiquette" referring to proper behavior on a network. Netscape* Netscape is a set of Web browsers, produced by Netscape Communications Corporation. network A group of interconnected computers, including the hardware and software used to connect them. node Any device connected to a network. N-type silicon Silicon created by adding phosphorus to produce an abundance of electrons and a negative charge. O offline Logically or physically disconnected from the computer, computer network, or the Internet. For example, a reel of tape is offline storage. A Web page that has been downloaded or saved so that it can be read while not connected to the Internet is for offline viewing. Ohm The unit of resistance exerted on the flow of electrons. online
The main control program of a computer that schedules tasks, manages storage, and handles communication with peripherals. Often abbreviated as OS or "o/s" optical disks and drives Optical disks are used to store computer or media data. Common formats include CD-ROM, CD RW, DVD, HD-DVD and Blu-ray. Optical drives use laser light to read the data stored on optical disks. Commonly, optical drives can record and read data. output The computer-generated information that is displayed to the user in some discernible form such as a screen display, printed page, or sound. P packet switching A transmission method for sending information on a network that allows many users to share the network structure in an efficient manner. packets The defined block of information consisting of header, data, and trailer that serves as the information exchange method on the network. pad A pad is envisioned as a blend of the features provided by a sheet of paper and the present laptop computer or personal digital assistant (PDA) that can be utilized and left where it was found for the next person to use. Pads would be available everywhere a person went to provide immediate access to online resources. PDF (portable document format) A platform-independent PostScript-based file format; part of Adobe Acrobat*. Acrobat can convert a DOS, Windows, UNIX, or Macintosh document into a portable document format (PDF) which can be displayed on any computer with Acrobat Reader*. peripherals Any device that is attached to a computer system or network, such as printers, disks, and tape drives. personal computer (microcomputer) A computer that serves one user at a time. personal digital assistant (PDA) A small, lightweight computer that provides a way to take notes and consult reference files while away from your desktop computer and also enables you to move files to and from your desktop computer. photoresist A light-sensitive material that changes chemically when exposed to light. physical address The number given to a device for identification purposes if the device becomes a node on the network. pixel Short for picture element. A pixel is the smallest logical unit of visual information that can be used to build an image. Pixels are the little squares that can be seen when a graphics image is enlarged. The more pixels in an image, the better its resolution. platform The underlying hardware or software for an operating system. The basic system on which applications execute. Two common platforms are PC and Macintosh. port A pathway for data flow in and out of a computer. A computer port is a receptacle for attaching input and output devices. primary storage The computer's immediate internal memory, RAM and ROM. processing The manipulation of data by a microprocessor or embedded processor according to instructions given to it by a program or embedded in the chip itself. program The set of instructions needed to accomplish a given task. protocols The rules or standards that determine how two or more processes communicate and interact to exchange data. P-type silicon Silicon created by adding boron to produce a material lacking in electrons, giving it a positive charge. public domain Belonging to the public; not protected by copyright. Q quadrupeds Four-footed animals. quality control A formal procedure used in manufacturing to ensure that the product being produced meets a specific standard. QuickTime* A multimedia player from Apple Computer that integrates full-motion video and sound into application programs that gives a seamless integration of video, sound, and animation. Also available as QuickTime for Windows. R RAM (random access memory) The memory that is available on a computer for storing data and programs currently being processed. It is automatically erased when the power is turned off. Information in the RAM that needs to be stored for future use must be saved onto a disk or a tape. registers Circuits on the microprocessor where values of internal operations can be temporarily stored, such as the addresses of instructions being executed and the storage location of data. remote terminal A terminal that is located at a distance from a host or network and is generally connected by telephone line. removable media A portable device allowing for the storage of computer data. Examples can include, Memory Sticks, magnetic tapes, CD-ROM, and DVD R. repeater A hardware device that functions at the physical layer of the network and is used to increase the strength of the signal at certain intervals so the signal is maintained. resistance A characteristic of material that opposes the flow of electrons. resistor A device with a measurable ability to impede the flow of electrons; used to adjust the strength of the current in a circuit. resolution A graphics formatting term: The number of dots per inch used to represent a graphic image. The term "pixels" is also used for "dots" in this context. High resolution images look smoother and have more dots per inch than do low resolution images. The resolution of images displayed on the screen is usually lower than that of the final laser printout. Laser printers print 300 dots (or pixels) per inch or more; typesetters print 1,200 dots (or pixels) per inch or more. ROM (read only memory) A system's permanent, stored instructions, which are never changed; it holds its contents even when the power is turned off. Data is placed in ROM only once, and stays there permanently. ROM is generally installed by the manufacturer as part of the system. router In a network, this device is used to determine the pathway used to transmit any signal between different network nodes. S scanner A computer input device that can read text, images, and bar codes and translate them into digital code that a computer understands. search directory A remotely accessible program that lets you do keyword searches for information on the Internet. A directory is a catalog of sites collected and organized by people. Subject directories are often called subject "trees" because they start with a few main categories and then branch out into subcategories, topics, and subtopics. Yahoo!* is the most common search directory. search engine A remotely accessible program that lets you do keyword searches for information on the Internet. There are several types of search engines; the search may cover titles of documents, URLs, headers, or the full text. Examples are Yahoo! Search*, Google*, and MSN Search*. secondary storage Storage that is not involved in the processing of information. This type of storage is used to maintain the digital information for later use. Includes such storage devices as hard disks, tape drives, and optical disks. semiconductor A material that when combined with some other material can be turned into an insulator or a conductor. sequence ID A number given to a chunk of data from a message so that the message can be reassembled in the correct order. server A server is a special device used to "serve" a system or facility. A server is a computer in a client/server architecture that supplies files or services. The computer that requests services is called the client. The client may request file transfer, remote logon, printing, or other available services. server A device that provides some type of network service such as access to files or devices, transport or translation facilities, and so on. shareware Software that is copyrighted, but may be downloaded and used for a limited time for free, after which the user is asked to voluntarily send the author a small payment. Some shareware products offer additional features, documentation, technical support, and/or updates to registered users. shortcut Microsoft Corporation's term for a symbolic link, often represented as an icon with an arrow integrated on it. On the Macintosh, Apple Corporation refers to a symbolic link as an alias. signal The electrical impulse representing data that is being transmitted from one place to another. silicon The most common element in nature and the material used to create most transistors and integrated circuits. silicon compiler An application that is able to produce the mask or pattern needed for a particular layer on the chip using the information that is contained in the circuit diagram. site An organization or facility where a host computer is located. See also Web site. smiley See emoticons. SMTP (simple mail transfer protocol) A protocol from the Internet suite (for example TCP/IP) that is used to send electronic mail between users on different host systems. software The programs and data that make computer hardware function. source The post of a transistor that receives the electricity from the circuit's pathway. speech recognition The ability of a computer or other electronic device to understand the spoken word. Speech recognition allows you to use just your voice to direct a device to perform a command or to take input. Instead of typing in a letter, for instance, you could simply dictate it to the computer. standards A rule set up and established by authority or custom for the measure of quantity, weight, extent, value, or quality of something. storage In computing, any device in which (or on which) information is stored. storyboard A series of panels on which a set of sketches is arranged depicting consecutively the important changes of scene and action in a series of shots in a film, animation, television show, or commercial. switch Any device that allows the flow of electricity in a circuit when turned on (completing the circuit pathway), or stops the flow of electricity when turned off (creating a break in the circuit pathway). T tab An envisioned small computer worn like a badge that allows tracking of the wearer's location, triggers automatic doors, allows telephone forwarding, and other conveniences meant to connect the person on the move with their home base. Taskbar A bar along the bottom edge (or side) of the Windows desktops that contains the Start button and a button for each program that is currently running. The taskbar can be used to switch from one task to another. It can also be dragged around with the mouse and adjusted in size. TCP/IP (transmission control protocol/internet protocol) A set of protocols used to allow computers to share resources across a network. These protocols support file transfer, remote logon, and electronic mail between users on the different host computers on the network. See also Internet IP address. text wrap A text formatting term: The ability to wrap text around graphic images on a page layout. Some desktop publishing systems have an automatic text wrap feature that will shorten lines of text when a graphic image is encountered. In other systems, you need to change the length of lines by changing the column margins or by inserting hard carriage returns to shorten the lines. See also word wrap. transistor A type of switch that contains no moving parts and uses electricity to turn itself on and off. U ubiquitous computing The use of computers that is prevalent and integrated into every facet of one's life to such an extent that the technology is virtually invisible but is just there to be used. unshielded twisted pair A type of network cable that is inexpensive but limited in performance. upload To transfer information stored in the user's system to a remote computer system. URL (uniform resource locator) The address for an Internet Web site, generally beginning: http://. A standard that specifies the location of an object on the Internet, such as a file or a newsgroup. See also domain name. V virtual Virtual refers to anything that seems real but is actually simulated by the operating system or applications. For example, virtual memory is really disk storage made to look like real memory. virus A program that replicates itself on computer systems by incorporating itself into other programs that are shared among computer systems. voltage The force or strength of the electrical pressure in a circuit. W wafer A thin, flat piece of semiconductor crystal used in the manufacture of microprocessors and integrated circuits. Circuit components are created on the surface of the wafer through a series of manufacturing techniques that include layering and etching. WAN (wide area network) A network whose elements may be separated by some distance; usually involves two or more LANs and dedicated high-speed telephone lines. WAV A popular format for storing audio files for Windows applications. Sounds are "true-to-life," but can result in very large files. Web See World Wide Web. Web address Another way of saying URL. A Web address or URL is the unique location name for a specific Web page. A good example is www.nasa.gov, the home page address of the National Aeronautics and Space Administration. Web site
The outline of a final object presented as a combination of three- and four-sided geometric shapes that are used to describe the shape of the object in the computer. wireless connection A term describing a computer network where there is no physical connection (e.g. a wire) between sender and receiver, but instead they are connected by radio signal. word wrap A text formatting term: Automatic adjustment of the number of words on a line of text, as they are being entered and displayed on the screen, to match the margin settings. The returns that result from automatic word wrap are called "soft" returns to distinguish them from the "hard" returns, which result when Enter is pressed to force a new line. World Wide Web Also known as WWW or Web. A hypermedia-based system for browsing Internet sites. It is named the Web because it is made of many sites linked together; users can travel from one site to another by clicking on hyperlinks. The World Wide Web is a network of information servers, principally the ones using HTTP to serve up HTML documents. The servers are linked, not in any tight or formal sense, but because an HTML document from one server might contain pointers to documents on many other servers. WYSIWYG (what-you-see-is-what-you-get) A text processing term: (pronounced "wizzy-wig") a term used to describe systems that display full pages of formatted text and graphics on the screen. Refers to the ability of a computer to display the same colors and resolution on the screen that will come out of the printer. Z Zip Data compression and file packaging programs for personal computers. An example is WinZip* or PKZIP*. It may also refer to IOmega Zip* drive products. |