AJAX is the way of exchanging data with a server, and updating parts of a web page – without reloading the whole page.
Example:- Ajax is used many web application like google, facebook, yahoo, twitter, youtube etc.
Why use Ajax?
Difference between Synchronous and Asynchronous?
Synchronous means that data is sent in a sequence and Asynchronous means that data is not sent in a sequence.
Synchronous waits for each operation to complete, after that only it executes the next operation. Asynchronous never waits for each operation to complete, rather it executes all operations in the first GO only.