title: How does AJAX work?
body: <p>What is the essence of AJAX? For example, I want to have a link on my page such that when a user clicks this link, some information is sent to my server without the reloading of the current page. Is that AJAX?</p>
  
  <p>I was able to get this behavior by using isoframes. In more details I put a link (let's say a small image) in a small isoframe. When the user clicks this link the browser reloads only the page in the isoframe.</p>
  
  <p>However, I think it is not an elegant way to reach the goal. I think I have to use AJAX. How does it work? Can a usage of XHTML solve the considered problem in an elegant way? Or do I need to use JavaScripts?</p>
  
  <p>I do not need much. I just want to have a small link which (after clicking) sent some information to server. Let say I have a "star-image" near a message. If a user click the star (he/she likes the message) star changes the color and my server update database (to remember that user likes the message).</p>