Before you start to think that Java is a boring little command-line language that can only spit out what you put in, consider the applet. As I said in the beginning of the Basics section, an applet is a program that runs within another application, usually a browser like Netscape Navigator or Internet Explorer. And being inside another program has its advantages and disadvantages, which we'll look at in a moment. But first, let's look at what a 'real' applet can do.

An applet can make a Web page truly interactive without requiring the server (where the Web page lives) to do a lot of computation. This is because the entire applet is downloaded to the user's computer and run using their hardware. Take a look at some examples.

One favorite site is at http://online.cctt.org/curriculumguide/content/physlets.asp. It has a bunch of interactive physics applets. You should go and play with some of them to get a feel for what Java applets can do.

Another good site is from those tricky people who created Java, at http://java.sun.com/applets/jdk/. They also provide the source code. It's fun to save the code and play with it, changing parameters to see how it affects things. Remember, one of the best ways to learn is to experiment.