Java Runtime Environment (JRE short) is the runtime environment for the Java platform of the Sun Microsystems named. It provides the Java Virtual Machine, and is required to view Java applications execute with free platform independence
Java Runtime Environment which is also referred to as Java Virtual Machine or as Standard Edition (JRE), establishes a connection between popular browsers and the Java platform. Java allows applications to be downloaded over a network and run within a guarded sandbox. Security restrictions are easily imposed on the sandbox.
Here is how you can download the full setup offline installer for java runtime environment