Controllers types

Hi All,

I want to know the different types of controllers in the web dynpro applications in detail.I know there are 5 types 1)Component controller,2)Custom controller,3)View controller,4)Component Interface controller,5)Component Interface View controller

So pls any one explain me in which situations we can use the above controllers what are the hook methods for each controller.It is very urget for me.

Regards

Seshu