Chapter 1, The Primer, explains that in order to get started with SignalR and real-time web applications, it is important to understand the motivation behind wanting to have such a technology and way of approaching application development.
Chapter 2, Persistent Connections, explains that at the core of SignalR sits something called PersistentConnection, and this is where everything starts. In this chapter, you will learn how to get started with it on the backend and consume it in the frontend.
Chapter 3, Hubs, enables us to move from persistent connections to one abstraction up: something called hubs. A hub provides a more natural abstraction for most scenarios. They are easier to write and easier to consume.