JDK & JVM - Java tutorial #2

The Java virtual machine (JVM) is a software implementation of a computer that executes programs like a real machine. The Java virtual machine is written specifically for a specific operating system, e.g., for Linux a special implementation is required as well as for Windows. A Java distribution typically comes in two flavors, the Java Runtime Environment (JRE) and the Java Development Kit (JDK). The JRE consists of the JVM and the Java class libraries. Those contain the necessary functionality to start Java programs. The JDK additionally contains the development tools necessary to create Java programs. The JDK therefore consists of a Java compiler, the Java virtual machine and the Java class libraries.