Java is an object-oriented programming language and have virtual machine platform that allows you to create compiled programs that run on nearly every platform whereas JavaScript is a scripting language that helps you create interactive web pages.

• You should consider Java if your project involves…

Android Apps

Enterprise Software

Scientific Computing

Big Data Analytics

General Purpose Programming of Hardware

• You should consider JavaScript if your project involves…

Dynamic single page applications (SPAs)

Front-End technologies like jQuery, AngularJS, Backbone.js, Ember.js, ReactJS etc.

Mobile App Development through PhoneGap, React Native, etc.