An applet is a tiny application built in Java. The applet is special in that it cannot easily access anything on your system outside of the browser. You can, though, now give the applet special privileges to do so. Applets can be found with such diverse functions as animation, image mapping, graphing, etc. When you add an applet to your page, you must have the class files present and correctly referenced for downloading to the client machine or the applet cannot run. This is true, also, of any other files that the applet uses. Usually, it is best to put all of the class files and associated files in the same directory. Most applets which you can download or purchase are limited in that they are not directly scriptable; i.e., you can place the applet on your page and fill in the associated parameters, but you cannot change those parameters on the fly.

In this tutorial, you will learn a little about applets and a little about using them in your pages. In order to develop the tutorial, we will use a sample applet which is derived from an idea presented in Java Unleased ,2nd Edition, Michael Morison et al.,Sams Net Publishing. The applet in its several versions was designed and compiled in Symantecs Visual Cafe.