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: Moreover, Java allows developers to make apps available on multiple operating systems at the same time because Java-based utilities. Java is a runtime environment maintained by Oracle that you must install on your Mac to be able to run applications written using the Java programming language.
