The Google Maps API allows third party developers to use the features of Google Maps on their own sites. Anything you can do as a user of Google Maps can be done using the Google Maps API. The Google Maps documentation home page is located at http://www.google.com/apis/maps/documentation/. The documentation is quite extensive. We will take a look at how the API basically works, and concentrate on the features we will use in our mashup. Just knowing how the API is organized is the key step in searching for information and using the Google Maps API in future projects.
The Google Maps API requires an API key. You can register for it for free at http://www.google.com/apis/maps/signup.html. This key is used when including the Google Maps API in your page. Before you do anything with Google Maps, you will need to get this API key and put this source tag and in top of your page’s head
tag.
<script src="http://maps.google.com/maps?file=api&v=2&key=Your Google API...