When to use an interface instead of an abstract class and vice versa?

Question

This may be a generic OOP question. I wanted to do a generic comparison between an interface and an abstract class on the basis of their usage.

When wou

Answer 1

This can be a very difficult call to make...

One pointer I can give: An object can implement many interfaces, whilst an object can only inherit one base class( in a modern OO language like c#, I know C++ has multiple inheritance - but isn't that frowned upon?)