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.

After you install Java and the JDK on Ubuntu, it's customary to set the JAVA_HOME environment variable as well. To do this, simply edit the user's environment configuration with the following command: ...

Setting the PATH variable allows you to launch programs via CLI from anywhere on your system. Here's how to set the PATH variable in Windows and make the most of it.

If you want to download and install Java JDK 18 on Windows 11/10 computer, you will also have to set up a Path in Environment Variable.

If Java is not recognized as internal or external command, you need to make sure that the installation is not problematic and its path is recognized as system variables.