What is the difference between AsyncPostBackTrigger & PostBackTrigger?

Question

What is the difference between AsyncPostBackTrigger & PostBackTrigger?

Answer 1

Here's a blog post which explains the difference:

In the template in an update panel, there are the options of an AsyncPostBackTrigger or a PostBackTrigger.

By default, controls outside of an update panel will trigger a normal synchronous post back. The AsyncPostBackTrigger “wires” up these controls to trigger an asynchronous post back. Conversely, controls declared inside an update panel will trigger an asynchronous call by default. The PostBackTrigger short circuits this, and forces the control to do a synchronous post back.