JAVA_HOME is an operating system (OS) environment variable which can optionally be set after either the Java Development Kit (JDK) or the Java Runtime Environment (JRE) is installed.

Learn how to set the PATH variable in macOS. The PATH variable is a file system environment variable that contains the location of commands and program files. In this article, you’ll learn how ...

If you want to play around with a Java preview feature, you'll first need a Java Development Kit. Here's how to install JDK 13 on Ubuntu and set the all-important JAVA_HOME variable.