There are two types of image maps is used : client-side and server-side
client-side extensions allow an application to place elements on an HTML form and respond to user events such as mouse clicks, form input, and page navigation.
server-side extensions allow an application to communicate with a relational database, provide continuity of information from one invocation to another of the application, or perform file manipulations on a server.
The map is defined using the <map> </map> tag.
inserting an image
<img src="image.jpg" >
when user click on this image, this message shows in popbox.