The main difference between OpenJdk and OracleJDK is licensing. OracleJDK: This article is based on the 'OracleJDK' ) (due to legacy), which is free for personal and development use but no longer free for commercial use.Popular OpenJDK builds includes Azul Zulu, Red Hat OpenJDK (IcedTea), Amazon Corretto, Eclipse Adoptium's Temurin, SapMachine, Microsoft OpenJDK, and more. It does not include web-browser plugin and Web Start. OpenJDK includes the virtual machine (HotSpot), the Java Class Library, and the Java Compiler. OpenJDK: Currently, the 'OpenJDK' ) developed by Oracle, Java community, Red Hat, Azul Systems, IBM, Microsoft, Amazon, Apple, SAP, provides a free and open-source Java Platform Standard Edition (or Java SE or JDK) official reference implementation.The system will not install a JRE that has an earlier version than the current version.The Java Development Kit (JDK), officially named 'Java Platform Standard Edition' or 'Java SE', is needed for writing and running Java programs. When you install the JRE, you can install only one JRE on your system at a time. To install an earlier version of the JRE, you must first uninstall the current version. To determine the current JRE version installed on your system, see Determining the JRE Version Installed on macOS.

However, the system will not replace the current JRE with a lower version.

When you install the JDK, it also installs the JRE. Administrator privileges are required to install the JDK and JRE on macOS. Installing the JDK and JRE on macOS is performed on a systemwide basis for all users. You cannot install Java for a single user. The following are the system requirements for installing the JDK and the JRE on macOS:

Brew install java runtime