The illustration shows some of the most important methods of the Page class that you can override in order to add code that executes at specific points in the page life cycle. The illustration also shows how these methods relate to page events and to control events. The sequence of methods and events in the illustration is from top to bottom, and within each row from left to right.
Note & Disclaimer:
This is not my own creation. I found it useful and worth posting it here so that others find it useful too.
Original complete article can be found here:http://msdn.microsoft.com/en-us/library/ms178472.aspx