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Acceptable Use Policy (AUP): A set of guidelines and expectations about how people conduct themselves online.

AVI: A format for online video. A file named “example.avi” is likely to be a full-motion video that can be played on a computer.

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Bandwidth: A measure of capacity for communications channels. For Internet connections, bandwidth is usually expressed in thousands of bits per second (kbps). A standard dial-up connection to the Internet, for example, typically has a bandwidth of approximately 56k (or 56,000 bits per second). Cable modems or digital subscriber lines (DSL) provide much higher bandwidth (see broadband).

Bit: Short for “binary digit,” a bit is the smallest element of computer storage. A single bit holds only one of two possible values, 0 or 1.

Black list: A list of Web sites (or URLs) to which access from a given workstation or user is specifically forbidden. Contrast with white list.

Boolean logic: A system of logic based on operators such as AND, OR, and NOT. In many search engines, search terms are linked with these Boolean operators to create more precise queries.

Broadband: A common reference to communications or Web access that’s faster than dial-up (56k). Broadband access includes cable modems and digital subscriber lines (DSL).

Browser software: The computer program used to view documents on the World Wide Web (for example, Netscape Navigator or Microsoft’s Internet Explorer).

Bulletin board: A computer system used as an information source and forum for a particular interest group. Bulletin boards typically show the postings and replies made by various participants.

Byte: The common unit of computer storage. A byte consists of eight bits (or binary digits) and holds the equivalent of a single character, such as the letter “a,” a dollar sign, or a decimal point. Larger numbers of bytes can be expressed as kilobytes (1,024 bytes), megabytes (1,048,576 bytes), and gigabytes (1,073,741,824 bytes).

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Cache: A place to store files locally for quicker access. Caches, which can be temporary or permanent, are used to speed up data transfer. Memory and disk caches are used in every computer to speed up instruction execution and data retrieval. Material in caches often remains even after it has been used or viewed.

Chat: Real-time Internet conferencing between two or more users. Chatting is usually accomplished by typing on the keyboard, not speaking, and each message is sent directly to the recipient.

Chat room: A virtual room where a chat session takes place. Technically, a chat room is really a channel, but the term “room” is used to promote the chat metaphor.

Click (or mouse click): A way of making a selection online.

Client: An application that runs on a personal computer or workstation and relies on a server to perform some operations. For example, an e-mail client is an application that lets you send and receive e-mail.

Client–server model: A network architecture in which each computer or process on the network is either a client or a server. Servers are powerful computers or processes dedicated to managing disk drives (file servers), printers (print servers), or network traffic (network servers). Clients are PCs or workstations on which users run applications.

Client-side: Any operation that is performed at the client workstation.

Content provider: An organization or person who creates information, educational, or entertainment content for the Internet. A content provider might or might not provide the software or network infrastructure used to access the material.

Cookie: A message given to a Web browser by a Web server. The browser stores the message in a file (generally called cookie.txt). The message is then returned to the server each time the browser requests a page from the server. Web sites often use cookies to track users and their preferences.

Crawler: See spider or Web crawler.

Cybersex: Online, real-time dialogue (usually text-based) that interactively describes sexual behavior and actions with one’s online partner for erotic purposes and expression.

Cyberspace: A term coined by William Gibson in his 1984 novel Neuromancer that refers to the Internet or to the online or digital world in general.

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Database: A collection of information organized in such a way that users—often both people and computer programs—can quickly select desired pieces of data.

Dial-up: The most common method for accessing the Internet. It involves making a connection from a user’s computer, by using a modem, over a standard phone line to an ISP. Contrast with “always-on” access methods such as cable modems or DSL.

Digital Subscriber Line (DSL): A class of technologies that use copper phone lines to establish high-speed Internet connections to homes and businesses.

Download: The act of copying data, usually an entire file, from a main source to a peripheral device. The term is often used to describe the process of copying a file from an online service to one’s own computer.

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E-mail: Short for “electronic mail,” e-mail is the transmission of messages over networks.

Encryption: Any procedure used in cryptography to convert plain text into cyphertext to prevent anyone but the intended recipient from reading it.

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File attachment: A method by which users of e-mail can attach files to messages (for example, sending a digital picture of a newborn in an e-mail announcing the birth).

Filter (or filtering): A type of technology that allows Internet material or activities deemed inappropriate to be blocked, so that someone using the filtered computer can’t access the material or participate in the activities.

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Graphics file: A file that holds an image. JPG and GIF are two popular formats for image files exchanged on the Internet.

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Hard disk: A computer’s primary storage medium, usually a fixed component within the computer itself.

Harvester: An automated program designed to collect e-mail addresses by scanning Web sites, bulletin boards, and chat rooms, among other things.

History file: The list, which most Web browsers maintain of downloaded pages in a session, that allows users to quickly review everything that’s been retrieved. History files can easily be cleared or altered.

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ICQ (“I Seek You”): A conferencing program for the Internet. Much like AOL’s Instant Messenger service, ICQ provides interactive chat and file transfer and can alert users when someone on their predefined list has come online.

ICRA: The Internet Content Rating Association ( ICRA provides toolkits for users to rate Web sites (and pages within those sites) with respect to their potential objectionable qualities (for example, the presence of sexually explicit material).

Instant Message (IM): A two-way, real-time, private dialogue between two users. A user initiating an IM sends an invitation to talk to another, specific, user who’s online at the same time. IMs are often used in conjunction with chat rooms. A user in a chat room can send an IM to someone else in the chat room whose screen name, or “handle,” is displayed, thus establishing a private communication.

Internet: A decentralized global communications network connecting millions of individual users and machines.

Internet Relay Chat (IRC): A conferencing system used on the Internet. Unlike instant messaging, however, users don’t communicate directly with each other. Instead, the server broadcasts all messages to all current users of a particular channel.

Internet Service Provider (ISP): An organization or company that provides access to the Internet. Examples of national-level ISPs include America Online (AOL), EarthLink, and Microsoft Network (MSN).

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Keystroke log: A method for recording each keystroke made by a user on a given computer.

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Link (or hyperlink): A reference or pointer to another document. Selecting (clicking on) a link on a Web page generally takes the user to the document being referenced (for example, clicking on a link to the NRC’s home page opens the NRC’s home page document in the user’s browser).

Login: The way computers recognize users. Logins are also commonly referred to as “user names.” Generally, the combination of a correct login and password is required to gain access

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Meta tags: Elements within HTML code that allow page creators to describe the content of Web pages. Meta tags are often read and indexed by search engines.

Metadata: A component of data that describes the data. Metadata describes the content, quality, condition, or other data characteristics. For example, in the HEAD section of most HTML documents, many Web page creators encode information about the title, author, date of creation or update, and keywords relating to or descriptions of the document’s content.

Modem: A device that enables the transmission of digital data over analog telephone lines.

Moderated newsgroup: A mailing list in which all postings are moderated by a person, the moderator, with the authority and power to reject individual postings that he or she deems inappropriate.

Mousetrapping: A technique that prevents a user from “escaping” from an objectionable Web site. Whenever the user tries to leave the site by closing the browser window or going to a new URL, the site that’s mousetrapping forwards the user to another, usually similar, Web site or launches a new window with the similar content. The result can be a never-ending stream of Web sites, which clutter the screen and often cause panic and distress to the user.

MPEG: Often used to refer to the files of digital video and audio data available on the Internet.

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Newsgroup: An online discussion group. On the Internet, there are literally thousands of newsgroups covering every conceivable interest.

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Offline: The time that a user isn’t connected to the Internet.

Online: The time that a user is connected to the Internet.

Overblocking: A practice of Internet filtering software that blocks access to resources that the filter users didn’t intend to block. Contrast with underblocking.

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Password: A secret series of characters that allows a user to access a file, computer, network, or other system. On multiuser systems, each user must enter his or her correct user name and password combination before the computer will respond to commands.

Peer-to-peer network: A communications network that allows all computers in the network to act as servers and share their files with all other users on the network. Napster is one example of peer-to-peer networking on the Internet. Also known as P2P.

Platform for Internet Content Selection (PICS):
A system endorsed by the World Wide Web Consortium for rating Website content.

Plug-in: An auxiliary program that works with Internet browser software to enhance browser capability. Examples include RealNetwork’s RealPlayer or Microsoft’s Media Player.

Portal: A Web site or service offering a broad array of resources and services, such as e-mail, search engines, subject directories, and forums. Yahoo! is an example of a portal.

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Real-time audio or video: Communication of sound or images over the Internet that occurs without delay in real time, much like a telephone conversation.

Remote viewing: The capability of system administrators—whether they be information technology help-desk personnel or teachers in a classroom—to view what’s being displayed on a given workstation or computer from their own locations.

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Scanner: A device that can copy text or illustrations printed on paper and translate the information into a form that can be used on a computer.

Screen name: An alias, or short nickname, chosen by a computer user to use when accessing his or her online service or network account. See login.

Search engine: A program that searches documents or indexes of documents for specified words or phrases and returns a list of the documents where those items were found.

Server: A computer, as well as the software running on it, that delivers, or “serves up” Web pages.

Server-side: Any operation that is performed at the server.

Spam: Unsolicited e-mail in general, but particularly unsolicited e-mail of a commercial nature.

Spider: A computer program that automatically retrieves Web documents. They are often used to feed pages to search engines for indexing. Also known as a Web crawler.

Streaming media: refers to a technique for transferring data so that it can be processed as a steady and continuous stream (as distinct from the user’s needing to download the entire file before being able to watch or listen to it).

Surfing (or Web surfing): is a metaphor for browsing the contents of the Web.

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Teaser: A Web page or portion of a Web site intended to entice users to spend more time at a given Web site or become paying customers.

Top-level domains: Major subdivisions within the Internet’s domain-name service (DNS). Examples of top-level domains include .com, .gov, and .edu.

Traffic: The load on a given Web site or resource. A high-traffic Web site, for instance, receives many visitors or requests for data.

Traffic forwarding: The practice whereby one Web site forwards traffic to another Web site and might receive a fee for doing so.

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Underblocking: A practice of Internet filtering software that does not block access to resources that authorities intended to block. Contrast with overblocking.

Uniform Resource Locator (URL): The address of documents and other resources on the World Wide Web.

Usenet: A worldwide bulletin-board system that can be accessed through the Internet or through many online services. Usenet is made up of more than 14,000 forums, called newsgroups, that cover different interest groups.

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Virtual hosting: The ability of Internet service providers or Web site operators to “host” Web sites or other services for different entities on one computer while giving the appearance that they exist on separate servers. With virtual hosting, Web sites from two separate organizations can reside on and be served by a single server (with a single IP address).

Virus: a type of replicating computer program that travels from computer to computer, most often through network connections that deliver e-mails or attached files. Computer viruses often spread without a user’s knowledge and may or may not cause disruption, lost or erased files, or other computer-data damage to the infected computer.

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Web crawler: A computer program that automatically retrieves Web documents. It’s often used to feed pages to search engines for indexing. Also called a spider.

Web page hosting: The ability of an Internet service provider, company, or other organization to act as servers of Web pages.

Webcam: A video camera that is used to transmit periodic images or continuous video to a Web site for display.

WebTV: A service that makes a connection to the Internet via a user’s telephone service and then converts the downloaded Web pages to a format that can be displayed on a television.

White list: A list of Web sites (or URLs) to which access from a given workstation or user has been specifically approved. Contrast with black list.

Workstation: A computer connected to a network (often the Internet).

World Wide Web (WWW): refers to the set of all the information resources that can be accessed via HTTP.

World Wide Web Consortium (W3C): One of the main standards bodies for the World Wide Web. The W3C works with the global community to establish international standards for client and server protocols that enable communications on the Internet.

Worm: A program that can copy itself from computer to computer. Worms normally travel and infect other machines through computer networks. Worms differ from viruses in the way they reproduce and spread. Viruses depend on a host file or a “bootstrap” record found on a floppy disk or hard drive and a transfer of files between computers. A worm can run independently and spread on its own.

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