Flash is an animation program that can create compact but high quality multimedia files for embedding into web pages, enabling them to download and display on screen fairly quickly. Flash files, frequently called movies, can include sound, graphics and animation, and can produce impressive screen displays and actions. Flash has developed to such an extent that entire websites are sometimes created as a complete Flash Movie.

Although they look impressive, Flash sites have one serious drawback - they can't be accessed by the major search engines.  Consequently, the content within the Flash movie cannot be read by the search engines and therefore cannot be listed.  This isn't too serious for a single Flash movie on a single page, but could have a dramatic effect on search engine placement if the entire site is constructed in Flash.