ment is run at the client site or decompressed at the client site. The conversion to the binary form saves the bandwidth and transmission time. The client can also store the retrieved document SO that it can run the document again without making a request to the server. The steps from the creation to the execution of an active document are: The programmer writes the program to be run on the client. The program is compiled and the binary code is created. The compressed document is stored in a file at the server. The client sends a request for the program. The requested copy of the binary code is transported in a compressed form from the server to the client. The client changes the binary code into executable code. The client links all the library modules and prepares it for execution. The program is run and the result is presented by the client. Java is an object-oriented language that is popular for developing Applet pro- grams to be run on the client as active documents. Java has a class library allowing the programmer to write and use an active document. An active document written in Java is known as an Applet. Java is a combination of high level programming language, a run time environment, and a class library allowing the programmer to write an active document that can be run on a browser. It should be noted that Java program does not necessarily need a browser and can be executed as a stand-alone program. Private data, public methods, and private methods can be defined in the Applet. An instance of this applet is created by the browser. The private meth- ods or data are invoked by the browser using the public methods defined in the Applet. In order to execute the Applet, first a Java source file is cre- ated using an editor. From the file, the byte code is then created by the Java compiler. Fundamentals of EMS, NMS and OSS/BSS This is the Applet that can be run by a browser. An HTML document is then created and the Applet name is inserted between the <APPLET> tags. Java is just one of the programming languag