Node.js is a platform built on Chrome's JavaScript runtime for easily building fast and 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 = Runtime Environment + JavaScript Library

Features of Node.js

Asynchronous and Event-Driven − All APIs of Node.js library are asynchronous, that is, non-blocking. It essentially means a Node.js-based server never waits for an API to return data. The server moves to the next API after calling it and a notification mechanism of Events of Node.js helps the server to get a response from the previous API call.

Very Fast − Being built on Google Chrome's V8 JavaScript Engine, the Node.js library is very fast in code execution.

Single Threaded but Highly Scalable− Node.js uses a single-threaded model with event looping. The event mechanism helps the server to respond in a non-blocking way and makes the server highly scalable as opposed to traditional servers which create limited threads to handle requests. Node.js uses a single-threaded program and the same program can provide service to a much larger number of requests than traditional servers like Apache HTTP Server.

No Buffering − Node.js applications never buffer any data. These applications simply output the data in chunks.

License − Node.js is released under the MIT license

Where to Use Node.js?

The following are the key areas where Node.js is widely used:

a. I/O bound Applications

b. Data Streaming Applications

c. Data-Intensive Real-time Applications (DIRT)

d. JSON APIs based Applications

e. Single Page Applications