What is the difference between the JDK and JRE?
The Java Development Kit contains the software and tools that you need to compile, debug, and run applets and applications that you’ve written using the Java programming language. The JDK TM software and documentation is free. The Java Runtime Environment is a separate download that consists of the Java virtual machine, core classes, and supporting files. It is the runtime part of the Java Development Kit that software vendors can redistribute with their products.