In this context, "C" refers to either an existing superclass or an abstract superinterface. It represents the base entity that both classes E and F are extending.
A subclass is a class that extends another class (superclass) or implements an interface (superinterface). It inherits all the fields and methods of its superclass.
Superinterface: A superinterface is an interface that extends another interface. It serves as a blueprint for implementing multiple interfaces in Java.
Polymorphism is an object-oriented programming concept where objects of different types can be treated as objects of the same type, allowing flexibility and code reusability.