This document provides an introduction to Node.js. It discusses that Node.js is an event-driven, non-blocking I/O platform for building scalable network applications using JavaScript. It was created to address issues with traditional blocking I/O by using asynchronous programming. The document outlines benefits of Node.js like using JavaScript for server-side applications, non-blocking I/O, a large module ecosystem, and an active community. It also provides examples of core modules, writing simple modules, and creating an HTTP server in Node.js.