Image map

<IMG src="flamewar.gif" usemap="#mac-pc">

<MAP NAME="mac-pc">
<AREA SHAPE="RECT" COORDS= "0,0,75,75" HREF="pc.html">
<AREA SHAPE="RECT" COORDS= "75,0,150,75" HREF="mac.html"> 
</MAP>

This is a client-side image map

Older methods used CGI scripts on the server to determine which URL would be triggered by a given coordinate pair

The <map> ... </map> tags are invisible and may be anywhere within the html body of document.