Java SE JDK 6u45

What is Java?
Java is a programming language and software platform. Examples of applications that use Java are numerous and widespread but include web browsers, office applications and even mainstream games like Minecraft are based on Java.
What is Java JDK?
The Java Development Kit (JDK) is the full-featured software development kit for Java developers. It has everything the JRE has, but adds the compiler (javac) and tools (like javadoc and jdb). The JDK allows you to create and compile Java programs.