The client API enables users to connect to the server via WebSocket, and the server API initiates a Socket.io connection on the backend server. The Socket.io library has two parts - the client and the server API.

In this section, you'll learn how Socket.io transfer messages between the client and the server in a web application. Real-time Node.js applications such as forex trading, sports betting websites, chat applications, and many others use Socket.io. This tutorial assumes that you have a basic knowledge of building web applications with Express.js and Node.js. Before we start coding this project, let's see how Socket.io works. In this article, you'll learn how to send notifications between web clients and a Node.js server using Socket.io. It follows the WebSocket protocol and provides better functionalities, such as fallback to HTTP long-polling or automatic reconnection, which enables us to build efficient chat and real-time web applications. It is a highly performant and reliable library optimized to process a large volume of data messages with minimal delay. Socket.io is a popular JavaScript library that allows us to create real-time, bi-directional communication between clients and a Node.js server. Node.js has a built-in WebSocket module, but this module doesn't provide the functionalities required to build complex real-time applications this is why Socket.io exists. If you are looking to implement in-app notifications (kind of like Facebook / Instagram / Upwork etc.), Check out Novu, we bring you the whole solution without dealing with websockets / scaling / databases / servers. Compared to HTTP, WebSockets provide a lasting bi-directional client-server connection, making it possible for data to change in real-time without refreshing the page. WebSockets create a connection between a client and a server, allowing them to send data both ways client-server and server-client. Have you ever used a forex trading app or visited a sports betting website? You will notice that the data changes almost every minute these changes are possible with the help of WebSockets. This type of communication is an HTTP connection, suitable for applications where data doesn't change frequently. The browser displays the response as web pages to the user.

The server receives the request and sends an HTTP response containing the related files to the web browser.

The browser sends a request to the web server, asking for resources related to the URL.

A user provides a URL to the web browser.

App.post('/send-notification', (req, res) => ) will create a channel named with ` notification` form which we can identify which channel to be used where on client end and the next parameter is the data over that channel.

Android realtime notification socket io