Inheritance in java is a mechanism in which one object acquires all the properties and behaviors of parent object. The idea behind inheritance in java is that you can create new classes that are built upon existing classes. When you inherit from an existing class, you can reuse methods and fields of parent class, and you can add new methods and fields also. Inheritance represents the IS-A relationship, also known as parent-child relationship. The extends keyword indicates that you are making a new class that derives from an existing class. A class that is inherited is called a super class. The new class is called a subclass. There can be three types of inheritance in java: single, multilevel and hierarchical. In java programming, multiple and hybrid inheritance is supported through interface only.