Anybody explain me what is virtual point and where it will use and when and why?

1. Wrong forum
2. There is no such thing as a "virtual pointer", I think you are mismatching words from different things.

I think that the virtual pointer can be a reference in WWW.:)

I'm not sure what you mean vlad,
http://stackoverflow.com/questions/4658627/virtual-pointer

I think you're referring to a pointer to a virtual table function table.
They're used in polymorphism to allow overriding of base methods.

Try this will defintely help you
http://www.mybestnotes.co.in/cpp/vptr-and-vtable.php