An applet is a small program that is intended not to be run on
its own, but rather to be embedded inside another application.

The Applet class must be the superclass of any
applet that is to be embedded in a Web page or viewed by the Java
Applet Viewer. The Applet class provides a standard
interface between applets and their environment.

This interface corresponds to an applet's environment: the
document containing the applet and the other applets in the same
document.

The methods in this interface can be used by an applet to obtain
information about its environment.

When an applet is first created, an applet stub is attached to it
using the applet's setStub method. This stub
serves as the interface between the applet and the browser
environment or applet viewer environment in which the application
is running.

The AudioClip interface is a simple abstraction for
playing a sound clip. Multiple AudioClip items can be
playing at the same time, and the resulting sound is mixed
together to produce a composite.