Flash, a popular authoring software developed by Macromedia, is used to create vector graphics-based animation programs with full-screen navigation interfaces, graphic illustrations, and simple interactivity in an antialiased, resizable file format that is small enough to stream across a normal modem connection. The software is ubiquitous on the Web, both because of its speed (vector-based animations, which can adapt to different display sizes and resolutions, play as they download) and for the smooth way it renders graphics. Flash files, unlike animated but rasterized GIF and JPEG, are compact, efficient, and designed for optimized delivery.
Known as a do-it-yourself animation package, Flash 4 gives Web designers the ability to import artwork using whatever bitmap or illustration tool they prefer, and to create animation and special effects, and add sound and interactivity. The content is then saved as file with a .SWF file name extension. (The letters SWF stand for 'Shockwave Flash.')
Web users with Intel Pentium or Power Macintosh processors can download Flash Player to view Flash content, which performs across multiple browsers and platforms. Flash is lauded for being one of the Web's most accessible plug-in. According to an independent study cited by Macromedia, 89.9 percent of Web users already have Flash Player installed.