The keyword extends denotes subclassing. HelloWorld is a subclass of Applet. A new class with nothing in it is pretty useless. The Methods can be totally new, can wrap-around parent's methods, or can override parent's methods Class Variables and Methods Class variables are initialized when the class is first loaded. Instance variables are initialized when an object is created.
Class variables have the same value for all instances of a class.
In Java they are denoted with the keyword static . Note, this is not good programming style, but you should know scope. They are not available to subclasses. An abstract class must have at least one abstract method. An abstract class cannot be instantiated, and must be subclassed final A final class is declared as the last class of any subclass chain.