Features Of Node.js

Extremely fast: Node.js is built on Google Chrome's V8 JavaScript Engine, so its library is very fast in code execution.

No buffering: Node.js reduces the overall processing time while uploading audio and video files. Node.js applications never buffer any data.
Open source: It is open source so you can free download this and it is free of cost

     I/O is Asynchronous and Event Driven:

 All APIs of   Node.js library are asynchronous i.e. non-blocking. So 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. It is also a reason that it is very fast..

  Single threaded: Node.js follows a single threaded model with  event looping.

  Highly Scalable: Node.js is highly scalable because event mechanism helps the server to respond in a non-blocking way.

Application or Uses of Node.js

 It is used for developing real-time applications such as chats and gaming apps.

It is used for those programs which needs event-based server, as well as non-blocking driven servers. 

With help of Node.js, videos can be processed as they are uploading, saving time and making media widely accessible at a faster rate. Video and audio files that are uploaded to streaming video services like YouTube have to be processed in order to be viewed or heard by users all over the world