# What is Node.js?

Node is a platform built to run JavaScript on the server. What that means is, the same JavaScript that powers dynamic frontend applications can also now be used to handle server-side code. 

Officially, Node.js is defined thus:

> Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine


Important to note here is Node.js is a `runtime` and it comprises of the V8 JavaScript engine which is also used by Chrome browser, and in addition, it has some libraries built into it that makes it ready as a server-side platform.

Node is written in C++ programming language.

Node.js is useful in a number of real-world applications. For building JSON APIs, Single page Applications, Data Streaming Applications, I/O applications (it can also interact with the file systems and Operating system) etc.

Node.js is Asynchronous, Event driven, fast and is single-threaded with event-looping.