Node.js is a platform built on Chrome's JavaScript runtime for easily building fast, scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, perfect for data-intensive real-time applications that run across distributed devices. Node.js applications are written in JavaScript. The Node.js ecosystem is huge. Apart from the Node.js core, it offers NPM as the package manager for node packages, along with several supporting frameworks.