Chapter 9. Ajax
Ajax allows browsers to fetch data from the server without a page refresh, so you don’t get any of that flash and flicker so common in the browsing experience. Instead, Ajaxenabled Web pages look and feel much more like desktop applications: you click a button, and the data you want appears somewhere in the page. The whole page stays the same except for that data.
Using Ajax, for example, you can buy an item without the need for five or six page refreshes—you might just drag the item to a shopping cart icon, and behind the scenes Ajax would contact the server, get the price, display a checkout ...