The current trend with sophisticated web applications is to emulate desktop applications and veer away from the "feel" of a traditional website. With traditional websites, every interaction with the server would require a full-page postback that makes a complete round trip. As our web applications become more sophisticated, the need to send and retrieve data to and from the server increases.

If we rely on full-page postbacks every time we need to facilitate one of these requests, our app will feel sluggish and unresponsive as the user will have to wait for a full, round trip with every request. Users demand more from their apps these days, and if you think about the application we've written, the Like button is a perfect example. Having to send a full-page postback to the server just because we wanted to increment a counter by one seems like a lot of unnecessary overhead. Fortunately, we were able to easily rectify this using jQuery and AJAX. This is a...