Image maps (called a "clicker bull image") are the graphics which can access specified URL, when a specific domain is clicked with a mouse. It is an image. The domain on an image is given by defining a figure (a polygon, circular, rectangle) and its coordinates.
For example, the usage of displaying the information about the place if the arbitrary places on a map are clicked can be considered. If an image map is used well, appearance is good and can make the page in which those who read tend to do navigation.