we can see use of AJAX in Google Maps, Gmail, Facebook, Youtube
Advantage of Ajax.
There is no need to buy extra software.
Whole page will not refresh only part of the page is refresh
We can access database from server without reloading page.
This is looking like desktop application.
Waiting time more reduced
Disadvantage of Ajax.
Anyone can view source code that is written for Ajax.
Ajax integration with every browser is not good.
Ajax code is complex that is more difficult to web developers.
Ajax application does not index on search engines like google,yahoo etc.
Data is URL-encoded so that that increased request.
By jQuery AJAX methods, we request and send data to the server. like web request data from XML, JSON, HTML, Text format. we can also send to datato server like php page , jsp page etc.