By definition, Node.js is a Java Runtime Environment (JRE). But it is more than just that. While common JREs serve as machine backups that allow users to smoothly run JavaScript on their browsers and applications, this open-source project functions as an app that manages Java code by itself. It's practical uses for developers are endless.

WTF!?!?! NodeJS is NOT a JRE, NodeJS is Javascript ran on top of the V8 engine which is built on C++. Where did you take that NodeJS has anything to do with Java?
Java's re-implementation of Javascript is something called Nashorn.

Where you got this thing from????