Five years ago, if you didn’t know XML, you were the ugly duckling whom nobody talked to. Eighteen months ago, Ruby came into the limelight and programmers who didn’t know what was going on with Ruby weren’t welcome at the water cooler. Today, if you want to get into the latest technology rage, Ajax is where it’s at.
Web applications are usually up-to-the-second current and they provide services you could never get on your desktop (think about Amazon.com and eBay). However, with the power of the Web comes waiting – waiting for a server to respond, waiting for a screen to refresh, waiting for a request to come back and generate a new page.
Obviously this is a bit of an oversimplification, but you get the basic idea. As you might already be suspecting, Ajax attempts to bridge the gap between the functionality and interactivity of a desktop application and the always-updated Web application. You can use dynamic user interfaces and fancier controls like you’d find on a desktop application, but it’s available to you on a Web application.