This second type is commonly referred to as client-side image maps.
Image maps require an image as well as a map of the image.
The map includes coordinates of different shapes and the URL associated with the shape. If you store image map information on a server, you need a script or other service on the server to process click information. In this example, the image map information is in the file named world.map. When the user clicks the picture in world2.gif, the server receives the coordinates of the click and can pick the appropriate destination for the click by checking the information in world.map. If you include the image map information in your document, the browser processes the click information and picks the appropriate destination for the click.