JavaScript: Moving to ES2015

Introduction to Socket.IO

Socket.IO is a combination of the client-side JavaScript library and Node.js library used to integrate bidirectional communication between a browser and Node.js backend.

The Socket.IO client-side library is used to create a Socket.IO client whereas the Socket.IO Node.js library is used to create a Socket.IO server. The Socker.IO client and server can communicate with each other bidirectionally. Socket.IO primarily uses WebSocket to achieve bidirectional communication.

The main reason for using the Socket.IO client-side library instead of using the WebSocket API is that WebSocket is a relatively new protocol at the time of writing and not all browsers support the API. If Socket.IO sees that the browser doesn't support WebSocket, ...