Here are some useful links about WebSockets and WebHooks, for .NET, GoLang, JS
Moving Data over the Web: AJAX vs. WebSockets vs. Webhooks
"HTML5 WebSockets allow your client-side JavaScript to open and persist a connection to a server. With WebSockets, data is exchanged as messages, which can happen very quickly due to the persistent connection.
Moving Data over the Web: AJAX vs. WebSockets vs. Webhooks
"HTML5 WebSockets allow your client-side JavaScript to open and persist a connection to a server. With WebSockets, data is exchanged as messages, which can happen very quickly due to the persistent connection.
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powerful aspect of WebSockets is a capability called full duplex, which is a fancy way of saying that both the Client and Server can send each other messages
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A Webhook is really just a URL that accepts a HTTP POST (or GET, PUT, DELETE). One server/service will provide another with a callback URL that it should push data to when it has some data to send. Any old web server can be used really."
WebSockets - Web APIs | MDN
Writing WebSocket client applications - Web APIs | MDN
WebSocket - Wikipedia
Webhook - Wikipedia
"A webhook in web development is a method of augmenting or altering the behaviour of a web page, or web application, with custom callbacks. These callbacks may be maintained, modified, and managed by third-party users and developers who may not necessarily be affiliated with the originating website or application."
gorilla/websocket: A WebSocket implementation for Go.
aspnet/WebSockets: Implementation of the WebSocket protocol, along with client and server integration components. @ GitHub
aspnet/WebHooks: Libraries to create and consume web hooks on ASP.NET Core
"Note: This repo is solely for the ASP.NET Core WebHooks projects (libraries to consume WebHooks on ASP.NET Core 2.0 and .NET Standard 2.0). For ASP.NET WebHooks (targeting .NET Framework 4.5), see the aspnet/AspNetWebHooks repo."
Sending WebHooks with ASP.NET WebHooks Preview | ASP.NET Blog
socketio/socket.io: Realtime application framework (Node.JS server)
How many system resources will be held for keeping 1,000,000 websocket open? - Stack Overflow
How do push notifications work? What is the basic concept behind them? - Quora
Push technology - Wikipedia
Adding Push Notifications to a Web App | Web Fundamentals | Google Developers
How does push notification technology work on Android? - Stack Overflow
600k concurrent websocket connections on AWS using Node.js - Jayway
Messaging in Distributed Systems - What's the Deal? - The Static Void Podcast