Web 2.0 vs Web 1.0

Why Ajax is Conceptually Better

Ajax has been around for quite some time now (it is a bit more than a year ago that Jesse James Garret coined the term) and it has quite some lovers, and just as many haters. First of all let’s distinguish between two different things that are often confused when we talk about Ajax.What many think to be Ajax are really two independent things:

• Asynchronous Communication: allows fetching and sending data asynchronously, in the background.
• DOM-Manipulation: which allows all those fancy Flash-like effects on web pages, such as zooming images, floating windows, but also really basic stuff, like swapping text in boxes.

Read more here