A Java applet is a special kind of Java program that a browser enabled with Java technology can download from the internet and run.
An applet is typically embedded inside a web page and runs in the context of a browser.
An applet must be a subclass of the java.applet.Applet class.
The Applet class provides the standard interface between the applet and the browser environment.
Swing provides a special subclass of the Applet class called javax.swing.JApplet.
The JApplet class should be used for all applets that use Swing components to construct their graphical user interfaces (GUIs).
Please make sure you have at least Java SE Development Kit (JDK) 6 update 10 release on your client machine before proceeding further.
You will need this to view the sample rich internet applications and read subsequent sections without interruptions.
Deployment Toolkit script can function properly.