# What is Node.js ?

This tutorial will explain to you what Node.js is and when we can use it.

Node.js is an open source server framework.

Node.js uses an event-driven, non-blocking I/O model that makes it lightweight and efficient. Node.js is build on small modules included in packages. A package is frequently referred to as a module since, usually it has one single module as an entry point. This modularity makes Node.js to have a small core. Node.js runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)

Node.js uses asynchronous programming => when a task is sent to the server the Node.js is not waiting for the response and can handle another request immediately. This great improvement is one of the strongest feature of Node.js.

What Node.js Can Do ?

• Node.js can generate dynamic pages
• Node.js can open, read, write, create, delete files on the server
• Node.js can serve static resources from the server
• Node.js can modify, add, delete data in your database

Because of its architecture Node.js is used to develop I/O intensive web applications like video streaming sites, single-page applications, and other web applications.