1. What is ASP.NET AJAX? ASP.NET AJAX, mostly called AJAX, is a
set of extensions of ASP.NET. It is developed by Microsoft to
implement AJAX functionalities in Web applications. ASP.NET AJAX
provides a set of components that enable the developers to
develop applications that can update only a specified portion of
data without refreshing the entire page. The ASP.NET AJAX works
with the AJAX Library that uses object-oriented programming
(OOP) to develop rich Web applications that communicate with the
server using asynchronous postback. 2. What is the difference
between synchronous postback and asynchronous postback? The
difference between synchronous and asynchronous postback is as
follows: 3. What technologies are being used in AJAX? AJAX uses
four technologies, which are as follows: 4. Why do we use the
XMLHttpRequest object in AJAX? 5. How can we get the state of
the requested process? XMLHttpRequest get the current state of
the request operation by using the readyState property. This
property checks the sta