Similar to GIFs in all attributes. Cannot create complex animation without creating immense file size. Dimensions are also limited because of size factors as well. Can be performed on almost every browser. Size limitations due to the fact each new image needs to be downloaded before effect can occur.
Image can appear with gradient patterns which add to depth and shadow.
With Flash other features can be attached. Pictures more illustrated in appearance than photo real. Can also simulate a Power Point-like slide presentation by calling up the next web page automatically. There still no pure standard that is shared equally between Netscape and Internet Explorer browsers, meaning what works with one, doesn't always work with the other. But there's hope on the horizon.