______________________________________________________________ Abstract: It is a class that can not be instantiated. Interface: it's a completely abstract class. Polymorphism: It means "many or multiple forms”. Overload: It is applied to the methods and constructors. Dynamic Link: It is what allows invoke operations on objects. Public: a declared public member is accessible anywhere in the program. Private: declared a private member can only be accessed by members of their own class. Protected: declared protected member behaves exactly like a private one.