AJAX uses the following technologies:
- CSS: the language used to style how the data will look onscreen
- XMLHttpRequest objects: the keystone of AJAX, they actually retrieve the data with the server behind the scenes. All modern browsers support XMLHttpRequests.
Callbacks vs. Postbacks.
Pre-AJAX, the rules for client calls to the server—basically, anything the browser requests from a database to make a site responsive—were “postbacks,” plus server-side processing. Post-AJAX, the browser can “callback,” requesting small amounts of data directly from the server—all without needing to wait for a postback.
What Advances have Been Made to Ajax?
By using jQuery and JSON Web Services, Ajax callbacks have become standard programming practices for designing and developing web applications.
The Ajax Control Toolkit is a suite of controls created by Microsoft that is integrated into Visual Studio and can be dragged and dropped onto web forms just like html and server controls. These controls are intended to be used for Ajax callbacks. However, they can also be used as normal client and or server controls. For example, Asp.Net does not come with the Tabs controls. However, the Ajax Control Toolkit does. The Tab control can postback to the server just like server controls.