Java is statically typed and a compiled language that can run on any OS so long as JDK is installed while JS is a dynamically typed scripting language that is interpreted line by line on a web browser. Java is a back-end language while JS is a front-end language with the exception of Node.js. Node.js differs from Java as it uses the Event Loop in it's runtime which relies on concurrent processing while Java uses the JVM which has the ability to do parallel processing.