How many types of triggers are present in update panel?
There are two types of triggers present in an update panel. These are the PostBackTrigger and the AsyncPostBackTrigger.
The PostBackTrigger works as full postback. It is somewhat similar to File Upload Control and is primarily useful to control the postback. However, it does not work asynchronously.
The AsyncPostBackTrigger does a partial post back, and it does it asynchronously.