• Java Runtime Environment :

    It physically exists. 

    The Java Runtime Environment provides

    the minimum requirements such as libraries

    and Class Loader for executing a 

    Java application on JVM. 

    It consists of the Java Virtual Machine

    core classes, and supporting files.

Under Java Platform, Standard Edition, select either the current release, or 

click Previous Releases to install an earlier supported version. You can use

either the JDK or JRE. The JDK includes the JRE. Do not use any non-supported

version or edition of the Java JRE or JDK.

cd android && ./gradlew --version