I am trying to learn AJAX, and I am referring to online material and some books. I came to know that AJAX isn't a new technology as such, however, it is a way of using existing technologies for "faster" web-applications (or changing some part of the web-page without refreshing the whole page).
Most of the code which I have seen in regards to AJAX, they are at client side (HTML, CSS and JavaScript). But how do I create a simple AJAX based web-application? I need something at the server side?
Can I used Apache Tomcat (and a servlet deployed) and URL mapping to fulfil a request initiated by a web-browser? Most of the books which I have seen, they haven't mentioned anything for what to do at server side, they talk only about the client side.
Can anyone help me how to approach in this regards?