The Java Runtime Environment (JRE) provides the backbone for running Java applications. The Java Development Kit (JDK) provides all of the components and necessary resources to develop Java applications.
The JRE is a collection of software that allows a computer system to run a Java application. The software collection consists of the Java Virtual Machines (JVMs) that interpret Java bytecode into machine code, standard class libraries, user interface toolkits, and a variety of utilities.
The JDK is a programming environment for compiling, debugging, and running Java applications, Java Beans, and Java applets. The JDK includes the JRE with the addition of the Java Programming Language and additional development tools and tool APIs. Oracle’s JDK supports Mac OS X, Solaris, Linux (Oracle, Suse, Red Hat, Ubuntu, and Debian (on ARM)), and Microsoft Windows (Server 2008, Server 2012, XP, Vista, 7, and 8). Additional operating system and special purpose JVMs, JDKs, and JREs are freely available at http://java-virtual-machine.net/other.html. Browsers supported are Internet Explorer (7.x, 8.x, 9.x, and 10.x), Mozilla Firefox (3.6 and above), Chrome, and Safari (5.1.3 and above).
Java Development Kits