Applets represent a shift in the basic model of web communications. In most other web applications, servers perform most of the computational work, client browsers being not much more than glorified terminals. With applets, web technology shifts to the client, distributing some or all of the computational load from the server to the client computer and its browser.
Applets also represent a way of extending a browser’s features without forcing users to acquire new browsers, as is the case when developers implement new tag and attribute extensions to HTML. Nor do users have to acquire and install a special application, as is required for helper or plug-in applications.[*] This means that once users have a browser that supports applets (all the currently popular ones do), you can deliver applets directly to the browser, including display and multimedia innovations.
Java-based applets—web page-referenced programs retrieved from a network server and executed on the user’s client computer—are an example of what the HTML 4 and XHTML standards call inclusions. As with images, the browser first loads the HTML document, then examines it for inclusions—additional, separate, and discrete content that the client browser is to handle. A GIF image is one type of inclusion. A .wav sound file, an MPEG movie, and a Java-based clock program are other types.
The HTML 4 and XHTML standards generally call the inclusion contents objects. In fact, in your document you ...