How to Install OpenJDK 15 on Ubuntu Gnu/Linux Distro
GNU/Linux Ubuntu Installing Java OpenJDK 15 Guide
How to Install Oracle-Sun OpenJDK 15 JRE/JDK on Ubuntu GNU+Linux desktop/Server.
And Java OpenJDK 15 for Ubuntu (Open Java Development Kit) is a Free and Open Source Implementation of the Java Platform, Standard Edition (Java SE).
Moreover, the Oracle Java JDK/JRE is based on the OpenJDK Source Code. In Addition, it contains Closed-Source Components.
