Java - A programming language that can be embedded in web pages. Java code is compiled into "bytecode" and is stored in "applet" files which have a ".class" extension. The language was developed by Sun Microsystems and is platform independent. It is a high-level interpreted language and requires a seperate program to interpret the code for it to run. In most cases the interpreter is either the web browser or a "Java Virtual Machine" running on the Operating System.

Javascript - A scripting language similar to Java (see Java), but developed by Netscape, that can be included within the HTML file (rather than in a seperate file). The web browser reads the Javascript and interprets it when loading the page. An common use of Javascript is to create "image rollovers": images that change when the user points to them with the mouse.

JPEG (Joint Photographic Experts Group) - A lossy compression technique that can shrink file size by 95% (but will lose image detail).

Meta Tag - A specialized HTML tag that provides information about the page, rather than how it should be displayed.

Multimedia - Images, sounds, or videos that can be embedded into a web page.

Navigation Bar - The toolbars available in a web browser application that allow you to navigate the world wide web.

Optimization - To compress or otherwise process an image so that it transfers quicker over the Internet.

Plug-In - A software module that adds a new feature to a system (for our purposes, the web browser is the system). A typical use for plug-ins is to allow the user to view new file types which are embedded into web pages, such as Shockwave and Flash.

PNG (Portable Network Graphics) - A new bitmapped graphics format designed to replace the GIF format because GIFs use a patented compression technique. The PNG format is patent-free.

Rollover Effect - An image on a web page that changes to a different image after a certain user action. For example, the user sees a picture that says "HOME" in blue text. They move the mouse pointer to the image and then a red glow appears around the text (a new image was actually loaded). This effect is most commonly created by embedding Javascript into the page.

Royalty Free Images - Images (such as clipart or stock photography) that can be used freely in any projects without giving credit to the creator of the image. Royalty Free does not imply that the image is free of charge (sometimes a license must be purchased).