This material has been prepared to accompany the book "Internet and Web Essentials" (ISBN 1887902460) by Ernest Ackermann and Karen Hartman, and published by Franklin, Beedle and Associates, Incorporated, Wilsonville OR, ©2000. No part of this may be reproduced, stored in a retrieval system, or transcribed without permission of the publisher.

Internet and Web Glossary

24-bit color A color system used in monitor display that provides 8 bits of information for each of the colors of the RGB system, allowing a total of 16,777,216 possible colors.

404 error A response code or error transmitted by a Web server to a client when a requested Web page or file is not present on the server.

absolute URL A URL (Uniform Resource Locator) that contains the Internet domain name of the server hosting the item to which the URL refers. For example, an absolute URL would be of the same form as The Internet domain name of this server is

acceptable use policy Within the context of the Internet, a policy that states the proper or acceptable uses of a computer network.

address box The pane in the browser window of Internet Explorer that holds the current document's URL. You can type a URL in this box and press Enter to access a Web page. See also location field.

administrative address The address to use to join an email discussion group or interest group and to send requests for services.

agent A program that gathers information or accomplishes tasks without your immediate presence. Agents are usually given very small and well-defined tasks. They are also called intelligent agents, personal agents, or bots.

all-in-one search tool A tool that provides search forms for several search engines and directories all in one site. The tool also provides hyperlinks that allow you to go to the services directly.

alternate text A description of a hyperlink or image, put in by the author of a Web page, that pops up when you move the mouse pointer over the hyperlink or image.

anchor element An HTML element that declares content to be a hyperlink to a URL that is specified as the value of the HREF attribute.

anonymous FTP A means of using FTP to make files readily available to the public. When you start an FTP session with a remote host, you give the login or user name "anonymous" and enter your email address as the password. When you use a URL that starts with ftp:// and a domain name with a Web browser, an anonymous FTP session begins, and you don't have to enter a user name or password.

article A message or file that is part of a Usenet newsgroup.

ASCII (American Standard Code for Information Interchange) A code for representing characters in a numeric form. An ASCII file is one that contains characters that can be displayed on a screen or printed without formatting or using another program.

asynchronous communication Communication where the sender and receiver don't participate at the same time, for example, email or voicemail.

attachment A file that is sent as part of an email message but that is not in the body of the message. Images, programs, and word-processing files are usually sent as attachments, because most email programs allow only plain text in the body of the message.

attribute Specifies a property of an HTML element. Attributes are found in the start tag of an HTML element and often take values.

avatar An icon, image, or figure that you can use to represent yourself in a chat room.

binary file A file containing information such as a compressed archive, an image, a program, a spreadsheet, or a word-processing document. The items in the file usually cannot be displayed on a screen or printed without using some program.

BinHex An encoding scheme that converts binary data into ASCII (American Standard Code for Information Interchange) characters.

blocking device See filter.

body element An HTML element that declares its contents of a document that is displayed by a browser.

bookmark list A list of links to items on the World Wide Web. Bookmark lists are usually created by individuals as they use Netscape. A good way to keep track of favorite or important sites, since they are saved and can be used at any time. See also favorites list.

Boolean searching Searching that uses Boolean operators (AND, OR, and NOT) in the search expression. Especially helpful in multifaceted or specific topics, Boolean operators help expand or narrow the scope of your search. A search for rivers OR lakes returns documents with either word in them. A search for rivers AND lakes returns documents with both words in them. A search for rivers AND lakes NOT swamps returns documents that mention both rivers and lakes but omits those that also mention swamps.

bot See agent.

bytecode The compiled format for Java programs. Once a Java program has been converted to bytecode, it can be transferred across a network and executed by Java Virtual Machine. Bytecode files generally have the extension "class," as in marquee.class.

cache A portion of memory (either in RAM or on a disk) set aside to hold the items retrieved most recently. For a Web browser, this refers to recent Web pages and images. The cache is used so that items may be retrieved more quickly without going back to the Internet. A browser can be set so that, in case an item hasn't changed, it will retrieve the item from the cache.

case sensitivity The ability of a search tool to distinguish between uppercase and lowercase letters. Some search tools aren't case sensitive; no matter what you type, the tool picks up only lowercase matches. Search engines that are case sensitive strictly follow a search request; they'll return documents containing the words in the case in which they were entered in the search expression.

cellpadding Space between the content of an HTML table cell and its border, specified in pixels.

cellspacing Space between cells in an HTML table, specified in pixels.

certificate authority A company that guarantees the identity of the holder of a digital certificate. A certificate is attached to a message or Web page and can be used to guarantee the authenticity of information.

CGI (Common Gateway Interface) A specification for transferring information between programs that execute on a Web server and the server software itself. A typical situation is for a so-called CGI program to take input from the server software, process it, and write the output in the form of a Web page that is then passed to a client by the server.

chat room A conference or forum that allows two or more people to converse with each other at the same time by taking turns typing messages.

client/server A program or Internet service that sends commands to and receives information from a corresponding program, often at a remote site, called a server. Most Internet services run as client/server programs. Telnet, for example, works this way. A user starts a client program on his computer that contacts a Telnet server.

content area The part of a Web browser window that contains the current Web page; it contains images, text, or hyperlinks.

commercial database A database that requires you to pay a subscription cost before accessing it. It is also referred to as a proprietary database.

Communications Decency Act of 1996 Legislation approved by Congress that made it a criminal offense to include potentially indecent or offensive material on the Internet. The U.S. Supreme Court ruled in June of 1997 that this act abridged the freedom of speech that is protected by the First Amendment, and the act was ruled unconstitutional.

compiler A program that translates a source file written in a programming language (that presumably a human can understand) into some form of machine language that can be dealt with by a computer.

compressed file A file that has been processed by a program that applied an algorithm or scheme to compress or shrink it. A compressed file must first be uncompressed or transformed before it can be read, displayed, or used. Files available through anonymous FTP are often stored in compressed form.

concept searching A feature enabling a search engine to find synonyms in its database. When you type in a word or phrase, the engine automatically searches for the word or phrase you want, plus words or phrases that may mean the same thing. For example, if the word teenage is in your search expression, the search engine also looks for the word adolescent.

conferencing A conferencing system generally uses text, audio, and video for holding group meetings and uses protocols that allow for these means of synchronous communication on the Internet.

cookie A relatively small piece of information that is initially placed on a client’s computer by a Web server. Once a cookie is present, the same Web server may read or rewrite the cookie. A Web server requests or writes a cookie to your computer only if you access a Web page that contains the commands to do that. Cookies are used to store information such as your login name and password or information about what portions of a Web site were visited on your computer. Sometimes viewed as an invasion of privacy, cookies are useful to you in some cases. Cookies can be used to keep track of your password or keep track of some preferences you’ve set for every visit to that site. You can set preferences in your browser to accept or reject cookies.

copyright The right to copy or duplicate material such as images, music, and written works. Only the owners of the information can grant this right. Regardless of whether information on the Internet or a Web page is accompanied by a statement asserting copyright, it is still protected by the copyright laws of the United States, the Universal Copyright Convention, and the Berne Union.

cross-posting Posting an article to more than one Usenet newsgroup.

data transfer rate The speed at which a circuit or communications line can transfer information, usually measured in bits per second (bps).

decoded Describes a file recreated in binary format that has been encoded or translated from binary to ASCII or text format. Binary files that are sent as attachments to email have to be encoded (translated from binary to ASCII) before they are sent and decoded (translated from ASCII to binary) when they are received before they can be used.

default setting The configuration a search engine uses unless you override the setting by specifying another configuration. For example, in some search engines, the Boolean operator OR is the assumed relationship between two words unless you type AND between the words.

delimited format A format often used to store tables of data. The data fields are separated by commas, tabs, semicolons, or some other delimiter. Spreadsheet programs usually include the facilities to import data that is in delimited format.

digital certificate A device that is used to encrypt and decrypt information, and to guarantee the identity of the sender and the authenticity of the information.

directory A topical list of Internet resources, arranged hierarchically. Directories are meant to be browsed, but they can also be searched. Directories differ from search engines in one major way - the human element involved in collecting and updating the information.

discussion group A group that discusses a single topic via email messages. An individual subscribes to or joins a discussion group electronically, and all messages sent to the group are distributed to the members by email.

dithered An approximation of a requested color using two or more available colors. Dithering sometimes occurs when an image or background on a Web page requires a color that isn't available on the computer displaying the Web page. In that case the computer approximates the color by mixing two or more colors it can represent.

domain name See Internet domain name.

domain name system A system of computers and protocols on the Internet through which an Internet domain name is translated into an IP address.

download To transfer or copy a file from another computer (the remote computer) to the computer you're using (the local computer). This term is often applied to the process of retrieving a file from a software library or FTP archive.

duplicate detection An output feature of some search engines and meta-search tools that automatically filters out of your search results any URLs that are duplicated elsewhere in the results.

ECPA (Electronic Communications Privacy Act) The U.S. law that prevents U.S. investigative agencies from intercepting or reading email messages without first obtaining a warrant.

electronic mail (email) A basic Internet service that allows users to exchange messages electronically.

element A distinctive part of an HTML document's structure, such as a title, heading, or list.

email client The program you use to work with your email. Also called the mail user agent.

email discussion group See discussion group.

emoticon A symbol that can be typed using one or more characters to foster more expressive and efficient communication. For example, :-) and :) are used to represent a grin or smile. These are also used to denote that a sentence is to be interpreted as a joke.

encoded Describes a file that's been translated from binary format to ASCII (American Standard Code for Information Interchange). This is done so the file can be sent using email.

encryption A procedure to convert a file or message from its original form to one that can only be read by the intended recipient.

event handler Java or JavaScript code that automatically responds to an event that occurs, such as the click of a mouse button.

fair use A provision in most copyright conventions or statutes that makes it possible for individuals to copy portions of a document or other piece of work for short-term use.

fan-in The receiving by an individual in a group of all the messages to the group. One person asks a question and replies can come from anywhere in the world.

fan-out The sending of one message to a group and having it automatically distributed or made available to every member of the group.

FAQ (frequently asked questions) A list, often associated with Usenet newsgroups, of commonly asked questions and answers on a specific topic. This is usually the first place users should look to find answers to questions or to get information on a topic.

favorites list The name that Internet Explorer gives to an individual's collection of favorite URLs. The browser includes menu bar and toolbar links to the favorites list. This list is similar to the bookmark list kept by Netscape. See also bookmark list.

field Part of a Web page or bibliographic record that is designated for a particular kind of data or text.

field searching A strategy in which you limit a search to a particular field. In a search engine, you might search only the URL field. By narrowing the scope of searchable items, field searching helps to eliminate the chance of retrieving irrelevant information.

file name extension The end of a file name in some operating systems where the name of a file ends with a period followed by (usually) two to four letters. The extension is used to associate an application program with the file. For example, the file containing this glossary is named glossary.doc. The file name extension is .doc. Clicking on the name of the file automatically opens the file with the Microsoft Word word-processing software.

filter Software that filters out certain Web sites from the results of a search.

firewall A security device or system, usually a combination of hardware and software meant to protect a local network from intruders from the Internet.

follow-up An article posted in response to another article. The follow-up has the same subject as the original article.

frame Some Web pages are divided into rectangular regions called frames. Each frame has its own scroll bar, and in fact, each frame represents an individual Web page.

freeware Computer programs that have been made available to the public free of charge.

frequently asked questions(FAQ) See FAQ.

FTP (File Transfer Protocol ) A means of transferring or sharing files across the Internet from one computer system to another.

FTP archive A collection of files available through anonymous FTP.

full-text indexing A search engine feature in which every word, significant or insignificant, is indexed and retrievable through a search. See also stop word.

group address The address to use to send email to each member of a discussion group, interest group, listserv list, or mailing list.

hexadecimal A numbering system that uses a base of 16. Computer programmers use hexadecimal numbers to represent binary numbers.

hierarchy A list of subjects in a directory. The subjects are organized in successive ranks with the broadest listed first and with more specific aspects or subdivisions listed below.

high precision/high recall A phenomenon that occurs during a search when you retrieve all the relevant documents in the database and retrieve no unwanted ones.

High precision/low recall A phenomenon that occurs when a search yields a small set of hits. Although each one may be very relevant to the search topic, some relevant documents are missed.

history list A list of Internet sites, services, and resources that have been accessed through a Web browser over a certain period of time.

home page The first screen or page of a site accessible through a Web browser.

HTML (Hypertext Markup Language) The format used for writing documents to be viewed with a Web browser. Items in the document can be text; images; sounds; or links to other HTML documents, sites, services, and resources on the Web.

HTML editor An application program designed to facilitate the writing of HTML. For example, the toolbars often contains icons and buttons that can be used to enter HTML tags.

HTTP (Hypertext Transfer Protocol) The standard protocol that World Wide Web servers and clients use to communicate.

hyperlink A word, phrase, image, or region of an image that is often highlighted or colored differently and that can be selected as part of a Web page. Each hyperlink represents another Web page; a location in the current Web page; an image, audio, video, or multimedia file; or some other resource on the World Wide Web. When the hyperlink is selected, it activates the resource that it represents.

hypermedia An extension to hypertext that includes graphics and audio.

hypertext A way of viewing or working with a document in text format that allows you to follow cross-references to other Web resources. By clicking on an embedded hyperlink, the user can choose her own path through the hypertext material.

IMAP (Internet Message Address Protocol) A protocol used to retrieve email from a mail server. It is similar to POP3 but has additional features.

implied Boolean operator The characters + and -, which can be used to require or prohibit a word or phrase as part of a search expression. The + acts somewhat like AND, and the - acts as NOT would in a Boolean expression. For example, the Boolean expression rivers AND lakes NOT swamps may be expressed as +rivers +lakes -swamps.

intelligent agent See agent.

interest group A group that discusses and shares information about a single topic via email.

Internet The collection of networks throughout the world that agree to communicate using specific telecommunication protocols, the most basic being Internet Protocol (IP) and Transmission Control Protocol (TCP), and the services supplied by those networks.

Internet domain name The Internet name for a network or computer system. The name consists of a sequence of characters separated by periods, such as The domain name is often the first part of the URL that follows ://. For example, the domain name in the URL is

IP (Internet Protocol) The basic protocol used for the Internet. Information is put into a single packet, containing the addresses of the sender and the recipient, and then sent out. The receiving system removes the information from the packet.

IP address An Internet address in numeric form. It consists of four numerals, each in the range of 0 through 255, separated by periods. An example is Each computer connected to the Internet has an IP address assigned to it. The IP address is sometimes used for authentication.

IP telephony Transmitting and receiving telephone messages via the Internet. Messages are broken into packets and exchanged using the Internet protocols.

IRC (Internet Relay Chat) A synchronous communication system on the Internet. An individual uses an IRC client to contact one of the several IRC servers on the Internet. Once connected, the individual joins a channel or chat room and can communicate in realtime with others using the channel.

ISP (Internet service provider) A usually commercial service that provides access to the Internet. Fees often depend on the amount of time and the maximum possible speed, in bits per second, of access to the Internet.

Java An object-oriented programming language. The language was originally designed to be used to develop applications in networked devices. It has been used very successfully to make small applications available through Web pages in a platform-independent format as bytecodes.

Java applet A Java program that can be included as part of a Web page.

JavaScript A programming language used exclusively within Web pages. The statements in the language are made part of a source file to enable some interactive features such as mouse clicks and input to forms. JavaScript is not based on or part of Java.

JPEG (Joint Photographic Experts Group) A file format used to represent images. It supports more colors than GIF and offers greater compression. However, some detail is lost in the compression.

keyword A descriptive or significant word in a Web document.

limiting by date A search tool feature that allows you to limit search results to pages that were indexed after, before, or between certain dates.

list address See group address.

Listserv The type of software used to manage a listserv list.

listserv list A type of discussion group, interest group, or mailing list.

location field The pane on the browser window of Netscape that holds the current document's URL. You can type a URL in this box and press Enter to access a Web page. See also address box.

Location toolbar The toolbar just above the content area in Netscape that includes the Bookmark Quickfile icon, which serves as a link to the bookmark list; the Page Proxy icon, which lets you add sites to the bookmark list, the personal toolbar, or the desktop; and the location field.

lossless A data compression scheme that doesn’t throw away or otherwise leave out any information from the original, uncompressed file. Graphic Interchange Format, GIF, uses a lossless compression scheme.

lossy A data compression scheme that excludes or removes information it regards as unnecessary from the original, uncompressed file. The Joint Photographic Experts Group format, JPEG or JPG, uses a lossy compression scheme.

low precision/high recall A phenomenon that occurs during a search when you retrieve a large set of results, including many irrelevant documents.

lurking Reading the email or articles in a discussion group or newsgroup without contributing or posting messages.

mail user agent See email client.

mailing list See discussion group.

menu bar The sequence of pulldown menus located across the top of the Web browser window. All commands are accessible from the menu bar.

meta-search tool A tool that provides either the ability to search more than one search engine or directory simultaneously or a list of search tools that can be accessed from its site. These two major types of meta-search tools are called parallel search tools and all-in-one search tools.

meta-tag A keyword inserted in the meta-tag portion of an HTML source document by the Web page author. If Web pages don't have much text, meta-tags help them come up in a keyword search.

MIME (multipurpose Internet mail extensions) Extensions to standard email programs making it easy to send, receive, and include nontext files.

MIME type Code that specifies the content type of a multimedia file.

modem The device used to allow a computer to communicate with another computer over a telephone line. It is needed because the computer’s information is in digital form and information on many telephone lines is transmitted in analog form. A device to convert from one form to the other is a modulator and demodulator, hence the term modem.

Moderator A person who manages or administers a discussion group, interest group, listserv list, mailing list, or Usenet newsgroup. In most cases the moderator is a volunteer. Messages sent to the group are first read by the moderator who then passes appropriate messages to the group.

MOO Similar to a MUD, but the enabling software is written in an object-oriented manner. This allows persons unfamiliar with the intricacies of the software to be able to set up and manage a MOO.

MUD Multiuser dimension or multiuser dungeon. Software that enables synchronous communication in a virtual world. It was originally designed to represent dungeons-and-dragons-type role-playing games.

natural language searching The capability of entering a search expression in the form of a question or statement.

navigation toolbar Often referred to as the command toolbar, this toolbar contains a sequence of icons or items that represent frequently used commands for navigation and other purposes, such as printing the current Web page.

nested Boolean logic The use of parentheses in Boolean search expressions. For example, the nested expression ( (rivers OR lakes) AND canoeing) NOT camping will find resources that contain first either the words rivers or lakes and then the term canoeing, but not resources that contain the term camping.

news server A computer that is used to hold the collections of articles that make up newsgroups, and to run the programs that pass any new articles posted to its newsgroups on to any other server that carries the same newsgroups.

newsgroup A collection of Usenet articles arranged by topic. Some are specialized or technical groups (such as - topics related to Internet domain style names), some deal with recreational activities (such as - topics related to saltwater fishing), and one, news.newusers.questions, is dedicated to questions from new Usenet users.

newsreader The software you use to read, reply to, and manage Usenet news.

NNTP (Network News Transport Protocol) The standard protocol used to distribute Usenet news between computer systems on the Internet in a form that machines can read and computers can access.

packet-switched network A message delivery system in which information is broken into small units (packets) and routed through a computer network using the most efficient route available for each. The packets may travel along different paths, but are reassembled into one message by the receiving computer.

parallel search tool A search tool or service that takes one search expression, submits it to several search services, and returns selected results from each. This is an example of a meta-search tool.

people finder A Web-based email or telephone directory. See also white page service.

personal agent See agent.

Personal home page A Web page used by an individual to give personal or professional information.

PGP Pretty Good Privacy, the name given to a public key encryption system for exchanging email in a secure, encrypted format. PGP was developed by Philip R. Zimmerman in 1991.

phrase searching A search feature supported by most search engines that allows you to search for words that usually appear next to each other. It is possibly the most important search feature.

plug-in A software application that is used along with a Web browser to view or display certain types of files as part of a Web page. Shockwave from Macromedia is a plug-in that allows the browser to display interactive multimedia.

POP (Post Office Protocol) The way many email programs retrieve messages from a mail server. Email is delivered on the Internet to the mail server and an email program running on a personal computer retrieves that email through POP.

post A message sent to an email discussion group or a Usenet newsgroup. Also, to send a message to an email discussion group or Usenet newsgroup.

PPP (Point-to-Point Protocol) A standard protocol that allows a computer with a modem to communicate using TCP/IP.

proprietary database see commercial database.

protocol A set of rules for exchanging information between networks or computer systems. The rules specify the format and the content of the information, and the procedures to follow during the exchange.

proximity searching A search feature that makes it possible to search for words that are near each other in a document.

public key encryption An encryption method that involves the use of two codes or keys. The two keys, one called the private key and the other called the public key, are assigned to an individual. Using the public key anyone can encrypt a message or file that can only be decrypted or decoded by the use of the corresponding private key.

reference work A resource used to find quick answers to questions. Traditionally thought of as being in the form of books (such as dictionaries, encyclopedias, quotation directories, manuals, guides, atlases, bibliographies, and indexes), a reference source on the World Wide Web closely resembles its print counterpart. A reference book doesn't necessarily contain hyperlinks to other resources, although it will often have hyperlinks within the document itself.

relevance A measure of how closely a database entry matches a search request. Most search tools on the Web return results ranked by relevance. The specific algorithm for computing relevance varies from one service to another, but it's often based on the number of times terms in the search expression appear in the document and whether they appear in the appropriate fields.

relevancy ranking A ranking of items retrieved from a database. The ranking is based on the relevancy score that a search engine has assigned.

results per page A feature of some search engines that allows you to designate the number of results listed per page. Search engines usually list 10 results per page.

robot See spider.

router A device (hardware) that transfers information between networks.

scroll bar The rectangular area on the right side of a window that allows you to move up or down in an open document. You move by clicking and dragging it or clicking on the arrow at the bottom of the bar.

search engine A collection of programs that gather information from the Web (see also spider), index it, and put it in a database so it can be searched. The search engine takes the keywords or phrases you enter, searches the database for words that match the search expression, and returns the results of the search to you. The results are hyperlinks to sources that have descriptions, titles, or contents matching the search expression.

Search expression The keywords and syntax that you enter into a search form. With this expression, you ask a search tool to seek relevant documents in a particular way.

Search form The rectangular pane or oblong box that appears on the home pages of most search tools. In this space, you enter a search expression.

shareware Software that you are allowed to download and try for a specified period free of charge. If you continue to use the program after that time, you are expected to pay a usually modest fee to continue using the product legally.

signature An optional portion of an email message consisting of information about the sender such as his full name, mailing address, phone number, etc. The signature is stored in a file and automatically included with each message.

smiley The emoticon used to denote a smile, a grin, or a joke. Two common forms of this emoticon are :) and :-).

SMTP (Simple Mail Transfer Protocol) The Internet standard protocol used to transfer electronic mail from one computer system to another.

source file The text file that contains the HTML tags for a Web page. A browser reads the source for a Web page from this file and then, using the HTML tags, displays the Web page.

spam Unwanted and unsolicited email. The electronic equivalent of paper junk mail.

specialized database A self-contained index that is searchable and available on the Web. Items in specialized databases are often not accessible through a keyword search in a search engine.

spider A computer program that travels the Internet to locate Web documents and FTP resources. It indexes the documents in a database, which is then searched using a search engine (such as AltaVista or Excite). A spider can also be referred to as a robot or wanderer. Each search engine uses a spider to build its database.

status bar The bar or rectangular region at the bottom of the browser window that shows several items of information regarding the transfer of a Web document to the browser. When the mouse is moved over a hyperlink it shows the hyperlink's URL. When a Web page is requested it gives information about contacting and receiving information from a server. During transmission it tells, in terms of a percentage, how much of the document has been transferred and indicates whether transmissions are being carried on in a secure manner.

stemming See truncation.

stop word A word that an indexing program doesn't index. Stop words usually include articles (a, an, and the) and other common words.

streaming media The method of displaying or playing media such as sound or video as it is being transmitted across the Internet rather than retrieving the entire file before displaying it.

subject category A division in a hierarchical subject classification system in a Web directory. You click on the subject category that is likely to contain either the Web pages you want or other subject categories that are more specific.

Subject guide A collection of URLs on a particular topic. Most easily found listed in virtual libraries, they are also referred to as meta-pages.

subscribe To join a discussion group, interest group, listserv list, or mailing list. You use this term when writing commands to join such a group and to list a Usenet newsgroup on your newsreader.

synchronous communication Communication where the participants participate at the same time. Chat is an example of synchronous communication.

syntax The rules governing the construction of search expressions in search engines and other databases.

tag A code used in HTML that identifies an element so that a Web browser will know how to display it.

TCP (Transmission Control Protocol) A protocol used as the basis of most Internet services. It is used in conjunction (actually on top of) the Internet Protocol. It allows for reliable communication oriented to process-to-process communication.

Telnet Allows for remote login capabilities on the Internet. One of the three basic Internet services, Telnet allows you to be on one computer and to access and log in to another.

text file A file containing characters in a plain human-readable format. There are no formatting commands such as underlining or displaying characters in boldface or different fonts. It is also called an ASCII file.

thread A collection of articles that all deal with a single posting or email message.

thumbnail A representation of an image in a size that's usually much smaller than its true size. For example, we may represent an image whose size is 100-by-200 pixels as a thumbnail of 25–by-50 pixels.

toolbar A sequence of icons or items in the window above the content area of a Web browser. Clicking on an icon or item executes a command or causes an action.

top-level category One of several main subjects in the top of a hierarchy in a directory's list of subjects.

truncation In the formulation of a search expression, truncation is used when you want to find all endings of a word. It is done by cutting off the end of the word back to the root, and replacing it with a symbol, usually the asterisk (*). When given such a request, a search engine or database will look for all possible ends of the word, in addition to the root word itself.

unified search interface A meta-search tool that allows searching several search engines simultaneously.

unsubscribe To leave, sign off from, or quit a discussion group, interest group, listserv list, or mailing list. You use the term when writing commands to end a relationship with a discussion group or to remove a Usenet newsgroup from the list of those you would regularly read.

upload Transfer a file from the computer system being used to a remote system.

URL (Uniform Resource Locator) A way of describing the location of an item (document, service, or resource) on the Internet and also specifying the means by which to access that item.

Usenet news A system for exchanging messages, called articles, arranged according to specific categories called newsgroups. The articles are passed from one system to another, not as email between individuals.

virtual community A collection of individuals who form a bond through electronic communication.

Virtual library A directory that contains collections of resources that librarians or other information specialists have carefully chosen and organized in a logical way.

virus A program or executable code that must be part of another executing program. Usually viruses change the configuration or cause havoc with a computer system. The viruses are hidden within some useful or standard program.

visual editor An application program that is used to edit or create documents or Web pages. It's visual in the sense that the software makes changes that you see immediately. Some examples of visual editors are Microsoft Word (a word processor) and Netscape Composer (used with Web pages).

Web browser A program used to access the Internet services and resources available through the World Wide Web.

Web page The information available and displayed by a Web browser as the result of opening a local file or opening a location (URL). The contents and format of the Web page are specified using HTML.

Web presence provider A commercial service (in most cases) that provides a Web server to host a Web site. Fees often depend on the amount of disk space available, monthly traffic measured in bytes, and types of services that are provided.

Web server A computer that is running the software and has the Internet connections so that it can satisfy HTTP requests from clients. In other words, it is a properly configured computer system that makes it possible to make Web pages available on the Internet.

white page service A Web search service that helps locate email or street addresses for individuals. Similar services for businesses and government agencies are called yellow page services.

wildcard A character that stands in for another character or group of characters. Most search tools use an asterisk for this function. Although a wildcard is most often used in truncation, it can also be used in the middle of words (for example, wom*n).

World Wide Web The collection of different services and resources available on the Internet and accessible through a Web browser.