Linux Java OpenJDK Installation Guide
The Linked Linux Tutorials Show You Step-by-Step How to Install Oracle-Sun Java OpenJDK JRE/JDK on GNU/Linux Distributions.
And the OpenJDK (Open Java Development Kit) is a Free and Open Source Implementation of the Java Platform, Standard Edition (Java SE).
Finally, the Official Oracle Java JDK/JRE Release is based on the OpenJDK source code. In Addition, it contains Closed-Source Components.