What is the meaning of __doPostBack function, and when is it used?

Question

I had problem triggering server side button click events so I found a solution on the net that I should do something like

Answer 1

simply said, it is used mainly by controls with AutoPostBack property

http://www.dotnetspider.com/resources/189-AutoPostBack-What-How-works.aspx

if you want to implement autopostback for your custom control, then you need to implement IPostBackDataHandler