Java is a general-purpose object-oriented programming language. Java language is originally developed by James Gosling (Sun Micro-systems) of USA in 1991. Java was designed for the development of software for consumer electronic devices like TVs, VCRs and such other electronic machines. Java-enabled browsers on the Internet requires a variety of support systems.

1. Internet Connection: Local computer should be connected to the Internet.
2. Web Server: A program that accepts requests for information and sends the required documents.
3. Web Browser: A program that provides access to www and runs Java applets.
4. HTML: A language for creating hypertext for the Web.
5. Applet Tag: For placing Java applets in HTML document.
6. Java Code: Java code is used for defining Java applets.
7. Bytecode: It is compiled the Java code that is referred to in the Applet tag and transferred to the user computer.
8. Proxy Server: An intermediate server between the requesting client workstation and the original server. It is typically implemented for ensuring security.
9. Mail Server: A computer system that facilitates exchange (sending and receiving) of electronic mails across the networks.

Java Environment:

It includes a large number of development tools and hundreds of classes and methods. The development tools are part of the system known as Java Development Kit (JDK) and the classes and methods are part of the Java Standard Library (JSL). It is also known as the Application Program Interface (API).

Java Development Kit:

The Java Development Kit is a collection of tools that are used for developing and running programs. It includes:

(i) appletviewer (for viewing Java Applets)
(ii) javac (Java Compiler)
(iii) java (Java Interpreter)
(iv) javap (Java Disassembler)
(v) javah (for C header files)
(vi) javadoc (for creating HTML documents)
(vii) jdb (Java Debugger)