There was a time when you could assume that if someone knew Java they also knew how to write an applet. With Java's growing popularity and the diminished use of applets, however, that assumption is no longer valid.
An applet is an AWT component (actually an AWT container—it can contain other graphical objects). Specifically, an applet must be a subclass of java.applet.Applet, which is a subclass of java.awt.Panel.
If you're into Swing, you can use the JApplet class to implement a Swing-based applet. Keep in mind, however, that Swing doesn't work well under Internet Explorer—and because IE doesn't come with the Swing classes built-in, the browser must download them from your Web server.
Every applet is an AWT object. Specifically, ...