JDK (Java Development Kit), which includes JRE plus the development tools (such as compiler and debugger), is need for writing as well as running Java programs. JRE (Java Runtime), which include a Java Virtual Machine and core libraries, is needed for running Java programs.
OracleJDK is no longer free for commercial use, but OpenJDK is still free. Clean up the JDK and the installation package (removed JavaFX, JavaEE, CORBA modules, deprecated Nashorn JavaScript engine). Java SE 11 LTS (18.9) (JDK 11) (September 2018): Extended var to lambda expression.Removed native-header generation tool javah. Introduced time-based release versioning with two releases each year, in March and September, denoted as YY.M. Java SE 10 (18.3) (JDK 10) (March 2018): Introduced var for type inference local variable (similar to JavaScript).Java SE 9 (JDK 9) (September 21, 2017): Introduced modularization of the JDK ( module) under project Jigsaw, the Java Shell ( jshell), and more.Also integrated JavaFX graphics subsystem. Java SE 8 LTS (JDK 8) (March 2014): Included support for Lambda expressions, default and static methods in interfaces, improved collection, and JavaScript runtime.Introduced Strings in switch statement, Binary integer literals, allowing underscores in numeric literals, improved type inference for generic instance creation (or diamond operator ), Catching multiple exception types and rethrowing exceptions with improved type checking. Java SE 7 (JDK 7) (July 2011): First version after Oracle purchased Sun Microsystem - aslo called OracleJDK.Java SE 6 (JDK 6) (December 2006): Renamed J2SE to Java SE (Java Platform Standard Edition).Introduced generics, autoboxing/unboxing, annotation, enum, varargs, for-each loop, static import. J2SE 5.0 (JDK 5) (September 2004): Officially called 5.0 instead of 1.5 (by dropping the 1.).
Included JFC (Java Foundation Classes - Swing, Accessibility API, Java 2D, Pluggable Look & Feel, and Drag & Drop). Also released J2EE (Java 2 Enterprise Edition) and J2ME (Java 2 Micro Edition).
Oracle JDK requires a commercial license from Oracle and businesses (since 2019) need to purchase a commercial license in order to receive software updates. OpenJDK is completely open source with a GNU General Public License. The main difference between OpenJdk and OracleJDK is licensing.
It does not include web-browser plugin and Web Start. OpenJDK includes the virtual machine (HotSpot), the Java Class Library, and the Java Compiler.
The Java Development Kit (JDK), officially named "Java Platform Standard Edition" or "Java SE", is needed for writing and running Java programs.