Java is a robust, general-purpose, high-level programming language and a powerful software platform. It is also object-oriented, distributed, portable and multi-threaded. Java follows the 'Write - once - run - anywhere' approach. All Java programs must run on the Java platform that has two components, the Java Virtual Machine (JVM) and the Java Application Programming Interface (API).
With Java API, many types of Java programs can be developed. These include
Java stand-alone applications: The Java stand-alone applications are the programs written in Java to carry out certain tasks. These applications run directly by the Java interpreter. A standalone application should be delivered and installed on each computer before it is run. It can have either a Command-Line Interface (CLI) or Graphical User Interface (GUI). You have already used a number of stand-alone applications such as text editors, word processors and games applications.
Java Applets: Java applets are the Java applications that are embedded inside HTML files and can be downloaded into a Java-capable browser (E.g. Netscape and Hot Java). An applet can perform tasks and interact with users on their browser's WebPages without using resources from the web server after being downloaded. Using applets, you can do anything ranging from animations to complete games and utilities that can be executed over the Internet.
Java Servlets: Java servlets are the Java programs that run on a web server to generate dynamic web contents.