GNU/Linux Xubuntu 20.04 Installing Oracle JDK Guide
You are Welcome! The Tutorial Shows You Step-by-Step How to Install Oracle Java Development Kit in Xubuntu 20.04 Focal LTS GNU/Linux.
And Java SE JDK for Xubuntu Focal is a Development Environment for Building Applications, and Components Using the Java Programming Language.
Furthermore, the Java OpenJDK (Open Java Development Kit) is the Free and Open Source Implementation of the Java Platform, Standard Edition (Java SE).
Where the Oracle JRE/JDK is based on the OpenJDK Source Code. In Addition, it contains Closed-Source Components.
Especially relevant: Java 13 is the First, Long Term Support Release.