SignalR is an amazing framework that delivers a real-time and bidirectional messaging platform. SignalR provides several options to reach its goal, but in this chapter we'll start simple and use the most basic API to set up a persistent and real-time channel: Hubs. A Hub is a special class that SignalR will expose to all the connected clients, allowing them to make Remote Procedure Calls (RPC) to it. Inside the Hub, the developer will also have a set of special objects to use in order to perform calls back onto the connected clients.
There is a very important detail to highlight: SignalR is composed of a server-side library and a set of client-side libraries. In every working solution, you will always need to use both; you will need to expose the server-side endpoints and connect to them using the most appropriate client library. SignalR will do the rest, and you will experience a very natural, simple, and bidirectional programming model.