This is getting a bit complex now but lets start off with the hard topic first - maps.
Lets take a look at why maps are so complex.
You must have been to a web site and clicked on a picture to get to the page you want. Well you have used an image map then. These maps need the browser to send the co-ordinates of where you clicked on an image, back to the server. The server then decides what page to send back to you. The disadvantages of using server maps is they are about half a billion times more difficult to get working and user viewing your page can only see co-ordinates when on the map.