To generate each image in an animation sequence, the server needs to transmit the entire frame, even if only a small part of the image has changed, resulting in slower animation. With GIF animations, just the part of the image that has changed can be transmitted. Most server-push animations are short, because they require the active participation of the server. Another source of animation on the Web is Netscape inline plug-ins . While plug-ins are necessarily platform specific, GIF animations have the advantage of working across all platforms.
Image maps allow users to access different documents by clicking different areas in an image.
Both present you with an image you can click to take you to a number of different sites. Using a server-side image map, however, the x and y coordinates of a click are sent to the server, and the server decides which URL you will see. With client-side image maps, on the other hand, the map that relates parts of the image to different URLs is stored in the actual file you are viewing. This saves a round-trip to the server and should present documents to you faster. With a client-side image map, you don't have to wait for the server to respond.