creation: 3/6/99, revised: 5/7/99, 01/25/00, 01/26/02, 07/22/02, 06/05/03
Java has single inheritance, only. This means that a child class inherits from only one parent class. Mostly this is all you need. But sometimes multiple inheritance would be convenient. Interfaces give Java some of the advantages of multiple inheritance without the disadvantages.
The chapter includes some small examples, but you will have to wait until you start programming graphical user interfaces to see interfaces used realistically. Interfaces are crucial to GUI programming.