

We should emphasize that OpenJDK is an official reference implementation of a Java Standard Edition since version SE 7. Note: the versions in italics are no longer supported.

Let's take a look at the Java SE history: Oracle strongly recommends using the term JDK to refer to the Java SE (Standard Edition) Development Kit (there are also Enterprise Edition and Micro Edition platforms). It's thus named because it contains more tools than the standalone JRE, as well as the other components needed for developing Java applications.

It contains a complete Java Runtime Environment, a so-called private runtime. JDK (Java Development Kit) is a software development environment used in Java platform programming.
