In traditional techniques client submits data to the server for processing and server send back refreshed contents to the client for this whole page is reload. This causes user must wait until page is completely load.
We can overcome this problem using Ajax
AJAX is stands for Asynchronous Java Script and XML, is a new programming approach (Ajax is not a programming language). Using Ajax we can refresh single part of a web page instead of whole page reloading, this makes client server communication very fast.
You can update only portion of a page which is necessary, instead of whole page reloading
Ajax sends only necessary data to the server, the server is not required to process all the elements
Using Ajax we can implement drag and drop functionality that can be used to used to make front end changes and then these changes submitted to the server.
Because of whole page reloading we have to wait for a long time, but Ajax work under cover and retrieves data because of that web application constantly updated.
Ajax application update itself behind the scene
Ajax are very fast responsive