There are two ways of
AJAX that can be implemented using AJAXToolkit. One is the most popular method,
Server Centric (using Update panel) and another one is Client Centric. There
are several reasons (given below) why the server centric became so much
Server centric takes very less time to implement.
From a developer point of view, it is very easy to implement.
Just put your controls inside an UpdatePanel and ScriptManager will do rest of
concentrate only on server side.
Requires less effort.
But everything in this world comes with a cost.
There are also several drawbacks that come along with this approach.
Though it does not show but internally it completes the whole
page life cycle once again, which actually violates the basics of AJAX. But for
an end user it never matters.
As it completes the total page life cycle again and hence for
better performance client centric is having an edge.
This is the most preferred approach for better performance.
It is completely in adherence to the rules of AJAX.
Though its time taking to implement, but its worthy to spent time