does overlaod happens in same class and override in different classes? am i right?

Question

polymorphism: does overlaod happens in same class and override in different classes? am i right?

Answer 1

Yupp.
Though you can overload global functions as well (those that are not in classes).

Answer 2

Not really. You can overload parent methods.
(So, overloading doesn't have to be in the same class).