A programming language developed by Sun Microsystems for adding animation and other action to web sites, Java was designed as a simplified language to help programmers avoid errors. Small Java-based software applications (called Java applets) can play back on your computer if your Web browser is Java compatible. (The leading browsers, such as Microsoft Internet Explorer and Netscape, are compatible.)

Joint Photographic Experts Group (JPEG or JPG)

A file format for color images developed by the Joint Photographic Experts Group committee. JPEG compresses graphics of photographic color depth better than competing formats like GIF, and it retains a high degree of color fidelity. (It can contain 16-24 million colors, compared to GIF's 256.) JPEG's smaller files are also quicker to download than GIF. You can choose how much to compress a JPEG file, but the smaller you compress it, the more color information you will lose. For this reason, GIF is considered better for simple line drawings and images with just a few hues, because such images can't afford to lose detail.