Below is a very simple example of how to create a basic websocket using node.js. Websockets are great for maintaining a server/client relationship without as much of the overhead of HTTP web traffic.
Today, websockets are used to build a magnitude of browser-based real-time applications (live chats, multiplayer games). Basically it’s a persistent connection between the server and client in which both applications can send data. Typically, long-polling or Flash have been used as alternatives.
First, you’ll need to install the “websocket” package using npm.
$ npm install websocket
In our example, the server will listen for connections and reply “hello” (to any and everything the client sends) then another message shortly after.
Once the server has been started, you can use the code below in any HTML5 browser (that carries websocket support) to establish a connection to the server. In this example, the client sends a “hello” message when it opens the connection and puts anything it receives into the #content div.