Java FAQ 1 - What is Inheritance?
Inheritance is a way to reuse code that has already been written. Some basic terminology about inheritance is useful to gain an understanding of it. The “superclass” is the class which will be inherit by the “subclass”. By declaring one class (that is the subclass) to inherit (by using the “extends” command) from another class (that is the superclass), the new class receives all of the public methods and variables from the superclass. The subclass also receives that ability to call private methods of the superclass by using the “super.classname( )” command.The following diagram is an example of inheritance:
All four of the subclasses, Sedan, Coupe, SUV, and Pickup inherit all public methods and variables from Vehicle, the superclass.