Difference between JDK and JRE

What is JDK?

JDK is an acronym for Java Development Kit that was released by Oracle Corporation as a binary product to help Java developers developing on Windows, Linux, Mac OS X, and Solaris. It is an implementation of Java SE, Java EE, or Java ME. It includes a private Java virtual machine (JVM) and various other components to complete the recipe for a Java application. It is the widely used software development kit (SDK). The main components of JDK are mainly: appletviewer, apt, extcheck, idlj, jabswitch, java, javac, jar, javah, javap, javaws, keytool, pack200, policytool, VisualVM, wsimport, jrunscript, xjc, etc.

What is JRE?

JRE stands for Java Runtime Environment that allows developers to run applications and applets written in the Java programming language. These applets allow developers to have a much greater online experience than simply interacting with static HTML pages. It is also a product of Oracle Corporation and contains a stand-alone Java Virtual Machine (HotSpot), a browser plugin, standard Java libraries, and a configuration tool. It is the most common Java environment installed on Windows PCs and is freely available for the official Java website.

Key differences

1. JDK is a basic requirement for developing Java applications. JRE is a plugin required to run Java programs.
2. JDK needs more disk space as it contains JRE along with various development tools. JRE is smaller than JDK, so it takes up less disk space.
3. The JDK includes a set of API classes, JRE, Java compiler, Webstart, and other important files needed to write Java applications and applets. The JRE includes the JVM, Core libraries, and other important components needed to run applications and applets written in Java.
4. JDK is a set of software used to develop Java-based applications. On the other hand, JRE is an implementation of Java Virtual Machine (JVM) that actually runs Java programs.
5. JDK contains JRE plus development tools while JRE is an implementation of JV