Ajax - Beyond the Four Lettering

What is it all about?

First lets start with some basic things. What's AJAX standing for - Asynchronous JavaScript and XML. It isn't a programming  language, but a way to use existing standards. AJAX is the art of exchanging data with a server, and updating parts of a web page - without reloading the whole page. It’s really several technologies, each flourishing in its own right, coming together in powerful new ways. Ajax incorporates:

• Standards-based presentation using XHTML and CSS
• Dynamic display and interaction using the Document Object Model
• Data interchange and manipulation using XML and XSLT
• Asynchronous data retrieval using XMLHttpRequest
• And JavaScript binding everything together

The above may sound more or less like aliens talking to you so lets say it one more time in human language.  Ajax is a way of programming for the Web. Data, content, and design are merged together into a seamless whole. When your customer clicks on something on an Ajax driven application, there is very little lag time. The page simply displays what they're asking for. If you don't believe me, try out Google Maps for a few seconds. Scroll around and watch as the map updates almost before your eyes. There is very little lag and you don't have to wait for pages to refresh or reload. To put it in two simple words - instant loading.

So lets go a little deeper and see what is happening and how. In the traditional Web application, the interaction between the customer and the server goes like this:

• Customer accesses Web application 
  
• Server processes request and sends data to the browser while the customer waits
• Customer clicks on a link or interacts with the application
• Server processes request and sends data back to the browser while the customer waits