An image-map is an image with clickable areas. The required name attribute of the <map>
element is associated with the <img>'s
usemap attribute and creates a relationship between the image and the map. The <map>
element contains a number of <area>
elements, that defines the clickable areas in the image map.
Example
<img src="planets.gif" width="145" height="126" alt="Planets" usemap="#planetmap">
<map name="planetmap">
<area shape="rect" coords="0,0,82,126" href="sun.htm" alt="Sun">
<area shape="circle" coords="90,58,3" href="mercur.htm" alt="Mercury">
<area shape="circle" coords="124,58,8" href="venus.htm" alt="Venus">
</map>
In the above example if you click the respectable area then you may reach to the different html files...
Credit: w3schools