What is the difference between synchronous postback and asynchronous postback?

Question

I am getting confused between trap and interrupt. As trap is software driven and interrupt is hardware originated. Every instruction of a program get executed in CPU then how trap and interrupt differs ? A detailed example can help out me. Thanks in advance.

Answer 1

The difference between synchronous and asynchronous postback is as follows:

Asynchronous postback renders only the required part of the page; whereas, synchronous postback renders the entire page for any postback.
Asynchronous postback executes only one postback at a time, that is, if you have two buttons doing asynchronous postback, the actions will be performed one by one; whereas, synchronous postback executes all the actions at once.
Asynchronous postback only modifies the update panel that raises the postback; whereas, synchronous postback modifies the entire page.

Answer 2

Asynchronous Postback triggers update the page partially without refreshing the whole page (AJAX)
Postback triggers update the complete page caused by complete post of the page to the server.

Hope this will help you understand these two concepts usually used in AJAX.