How to install Java on your computer To run Java apps, open JAR files or compile some source code into bytecode you’ll need to install Java. To download and install Java on Windows, MacOS or Ubuntu, ...

This post explains how to install Java or check which version is running on your machine. Install on any OS, and learn about the JDK.

Each version will be associated with a number, starting with 0. If you want to switch to Java 18, locate and type the associated number for Java 18 and hit Enter on your keyboard.