The Object Class

Because the root class in the hierarchy is the Object class, everything below it is an object. To interact with each other, objects require their own actions, called methods. These methods, which encode actions that are needed by all objects, belong to the Object class.

Every other class in the hierarchy inherits the methods of the root class. Inheritance is the handing down of methods from a "parent" class-called a superclass-to all of its "descendent" classes-called subclasses. Finally, instances acquire methods from their own classes. Any method created for the Object class is automatically made available to every other class in the hierarchy.