Introduction to Ajax

Ajax is a technology used by JavaScript to send data to, and receive data from, a server. Originally Ajax stood for Asynchronous JavaScript and XML, but now this meaning has been lost as JSON (which we learned about in Chapter 1, The Task at Hand) has begun to replace XML as the preferred format for packaging data, and Ajax requests do not need to be asynchronous.

Using Ajax will make your applications more dynamic and responsive. Rather than having postbacks whenever you need to update a part of a web page, you can load only the necessary data and update the page dynamically. With Ajax we can retrieve almost anything from the server, including HTML snippets to be inserted into the web page and static data to be used by the application. We can also call web services that provide access to things such as data and services that are only available on the server side.

Making Ajax requests

jQuery provides methods that make it easy to access web resources and call web services...