concept websocket in category javascript

This is an excerpt from Manning's book Node.js in Practice. Login to get full access to this book.

That’s where WebSockets come in. They’re conceptually like the TCP sockets we saw in chapter 7: a bidirectional bridge is set up between the client and server. To do this you need a WebSocket server in addition to your standard Express server, or plain old Node http server. Figure 9.6 illustrates how this works in a typical Node web application.

Figure 9.6. A Node web application should support both standard HTTP requests and WebSockets.

HTTP requests are short-lived, have specific endpoints, and use methods like POST and PUT. WebSockets are long-lived, don’t have specific endpoints, and don’t have methods. They’re conceptually different, but since they’re used to communicate with the same application, they typically need access to the same data.