How Does AJAX work

# In the classic web application, communication between the client (the browser) and the web server were performed directly, using HTTP requests.

# Classic Web Application Model: When the visitor requests a page, the server will send the full HTML and CSS code at once. Every time user requests data, same process occur which creates delay in response.

# AJAX Application Model: When using AJAX the page is loaded entirely only once, the first time it is requested. All requests for data to the sever will then be sent as JavaScript calls to this engine. The AJAX engine then requests information from the web server asynchronously. Thus, only small page bits are requested and sent to the browser, as they are needed by the user.
The engine then displays the information without reloading the entire page. This leads to a much more responsive interface, because only the necessary information is passed between the client and server, not the whole page. This produces the feeling that information is displayed immediately, which brings web applications closer to their desktop relatives.