A picture element, the smallest addressable element in a picture display or image. In computer displays, a logical rather than a physical element, which may or may not correspond to a system's dot pitch (the maximum physical resolution, or displayable physical dots, of a display).

An application that provides a Web browser with the ability to display or play additional types of media, such as streaming audio or video.

Portable Network Graphics. A newer graphics format for the display of images on the Web that support a 48-bit color depth (JPEG supports a 24-bit color depth). The PNG image format also supports transparency and was developed as a replacement for the GIF image format (which utilizes a patented compression scheme). Only supported in the most recent browsers.

Post Office Protocol, Version 3. An "incoming mail" server.

A variation of the JPEG image format that behaves similarly to an interlaced GIF image, with the image being progressively displayed, starting with a low-resolution version of the image. Not supported in some earlier browsers, such as the Netscape 4 browsers.

A method developed by Apple Computer for delivering video, animation, and audio files.

To update the display of a Web page (using the Refresh button in Internet Explorer or the Reload button in Netscape Navigator).

The location of a linked object within a Web site that is stated relative to the linking object.

A Web site that has compiled a searchable index of sites on the Web, such as Yahoo, Google, or AltaVista.

A computer on a network that responds to requests from clients.

A process or program that is executed from the server, rather than being downloaded and executed by a user agent (or browser).

A server-side application using the Java programming language to dynamically generate HTML code or pages in response to a client request. Similar to ASP.

Standard Generalized Markup Language. The parent markup language of HTML.

A means for freely distributing software so users can try it to see whether they like it. Users are encouraged to share the software with others, thus the term. If they like it, they're supposed to purchase it. Originally described software that had no time-out, but now loosely describes any software that users can evaluate before buying.

Synchronized Multimedia Integration Language. (Pronounced "smile.") An HTML-like language for describing multimedia presentations.

Simple Mail Transfer Protocol. An "outgoing mail" server (e-mail is sent to an SMTP mail server).

The start of a non-empty HTML element (<p>, for instance).

The content of a style sheet, composed of a selector and a declaration block. A selector specifies the object or element to which a style is to be applied and a declaration block contains one or more property declarations (property/value pairs, such as color: blue, for instance).

The content of the STYLE element or an external style sheet file (*.css), composed of style rules.

Scalable Vector Graphics. A relatively recent standard for displaying vector-based graphics over the Web.