Sourav's Blog

AJAX Introduction

AJAX = Asynchronous JavaScript and XML.
AJAX is based on JavaScript and HTTP requests.
AJAX is not a new programming language, but a new way to use existing standards.
With AJAX, a JavaScript can communicate directly with the server, with the XMLHttpRequest object. With this object, a JavaScript can trade data with a web server, without reloading the page.

Internet-applications have many benefits over desktop applications; they can reach a larger audience, they are easier to install and support, and easier to develop.
However, Internet-applications are not always as “rich” and user-friendly as traditional desktop applications.
With AJAX, Internet applications can be made richer and more user-friendly.

AJAX uses the XMLHttpRequest object

To get or send information from/to a database or a file on the server with traditional JavaScript, you will have to make an HTML form, and a user will have to click the “Submit” button to send/get the information, wait for the server to respond, then a new page will load with the results. Because the server returns a new page each time the user submits input, traditional web applications can run slowly and tend to be less user-friendly.

With AJAX, your JavaScript communicates directly with the server, through the JavaScript XMLHttpRequest object.