What is a Java and What version should I use?

Java is the programming language used by Minecraft Java edition, and thus Java is used to run it's servers. Within recent versions of Minecraft, the version of Java used to run the servers (and clients!) has become more critical. You can find a table below of the most suitable Java version for your server depending on the selected game version;

Minecraft VersionJava Version
1.16 and Below8

How do I change what Java version my server uses?

Changing your server's Java version is quite straight forward- simply head over to your server's console, then on the left hand side, select Startup from under the Configuration section. On that page, you can now change the Java version using the drop-down menu under the Java version box.