What is Ajax
Ajax stands for Asynchronous Javascript And Xml. Ajax is just a means of loading data from the server to the web browser without reloading the whole page.
Basically, what Ajax does is make use of the JavaScript-based XMLHttpRequest object to send and receive information to and from a web server asynchronously, in the background, without interfering with the user's experience.
Ajax has become so popular that you hardly find an application that doesn't use Ajax to some extent. The example of some large-scale Ajax-driven online applications are: Gmail, Google Maps, Google Docs, YouTube, Facebook, Flickr, etc.
jQuery provides several methods for AJAX functionality.
With the jQuery AJAX methods, you can request text, HTML, XML, or JSON from a remote server using both HTTP Get and HTTP Post - And you can load the external data directly into the selected HTML elements of your web page!
Different browsers implement the Ajax differently that means if you're adopting the typical JavaScript way to implement the Ajax you have to write the different code for different browsers to ensure that Ajax would work cross-browser.
But, fortunately jQuery simplifies the process of implementing Ajax by taking care of those browser differences. It offers simple methods such as load(), $.get(), $.post(), etc. to implement the Ajax that works seamlessly across all the browsers.
In the upcoming chapters you will learn how to load data from the server as well as how to send and receive data using HTTP GET and POST method through jQuery Ajax.