Java Classes (review)

The component classes that make up the AWT and Swing are related to each other by inheritance. The class that is the ultimate ancestor of all other classes is the class called Object. The class Object defines the basic nature of all Java objects. Much of what goes on behind the scenes when a Java program is running is defined by Object. Part of the Java class hierarchy looks like this:

The "clouds" convey the idea that these are class definitions, not objects. The diagram shows that the classes Boolean, Character, Component, String, and many others have Object as a direct ancestor. The cloud for the Component class is dotted to show that it is an abstract class.