You're probably familiar with image maps in regular HTML, where you can click on a part of a graphic that has hot spots on it, and depending on which hot spot you click, you'll go to a different page. For example, if you have a map of the United States, each state could have its own hot spot. Clicking on a state brings you to a page with detailed information about that state.
Combining rollovers with an image map can give you some extremely interesting and attractive results. Find out how to master this technique in Script 3.17.