Java , the so hot-a-language developed by Sun Microsystems designed especially for the Internet .The Language has been specially designed to create Multi Threaded , MultiPlatform executable programs for WebSites, Web Servers etc.

Why Multiplatform? Because it just compiles the source code to byte codes . The resultant file is a Class file.For it to work in more than one platform or environment the JVM(Java Virtual Machine) is supplied for that platform.The JVM in turn uses a Class loader to fetch bytecodes from the class file and load them .Now, the question arises as to what kind of executable program does the Java Compiler create . Applets and applications is the answer.

Applets are graphical window based , event driven Programs embedded in Html documents and can be executed only from the interface of the browser. They are not standalone as applications which are used to create text based programs . Oh! there is more to it . You can invoke the graphical windows class also from within an Java application.

The only difference comes up drawing a line of border between applets and applications is that Applets which are loaded by the Java Virtual machine shipped along the Browser restricts the applet within a security framework model. Simply put , a Browser does not allow standalone programs to run from it's interface which may involve Direct File handling or so . Applications are whereas executable standalone programs which do not require any external application to load it. Henceforth, they are not restricted by any security norms.

Applets are designed to achieve which an simple plain Html document can never achieve , Dynamism .How else one can emulate running an Program like the ones created by C++, VB, Delphi from inside a Browser.? . Applets add dynamocity by letting you create powerful graphics, animation , sound and video etc with less load on the webserver it is located and also interactivity with the user. However , Web Browser giants like Microsoft have recently introduced a new concept called DHTML which can be used to create dynamic web pages by integrating HTML with Javascript or Vbscript based on the new DOM(Document Object Model) from W3C (World Wide Web consortium) which treat every html tag like an object to be programmed. But it still lacks the power put up by a powerful Language such as like Java .