Deconstructing Ajax!

The Web 2.0 movement is a new approach to building Web applications that are more responsive and user-centric. You can think of it as a second generation or second wave of Web applications. One of the main differences is that users don’t have to click and wait while using a Web application. Instead, updates and changes can happen in the background while the user does something else.

One of the most common approaches to building Web 2.0 applications is something called Ajax. The term Ajax doesn’t describe a technology. Instead, it refers to a collection of existing technologies and the way that they work together to build Web 2.0 applications.

Ajax-style applications use the following technologies:

• XHTML and CSS to describe the interface
• DOM to locate and manipulate different parts of the interface and the data source
• XML and XSLT to describe and transform data for the application
• XMLHttpRequest object to request and load external data
• JavaScript to bind the other technologies together

In this article, I’ll explain a bit more about the role that each technology plays. Let’s start by looking at how the Ajax technologies react together.