You've already learned how to make an image link to another document.

You can also subdivide an image into regions that link to different documents, depending on where someone clicks. This is called an image map, and any image can be made into an image map.

A Web site with medical information might show an image of the human body and bring up different pages of advice for each body part. Or a map of the world could allow people to click on any country for regional information.