Now that we have a good idea about how PersistentConnection can be registered and then used in our applications, let's go deeper and start sending some data with it. As usual, in SignalR, we need a client and a server to establish a connection, and both parts can send and receive data. Here we'll see how a server can push messages to any connected client, and we'll analyze what a message looks like.

We already mentioned the fact that any communication from client to server could, of course, be performed using plain old HTTP, but pushing information from a server to any connected client without any specific client request for that data is not normally possible, and that's where SignalR really helps.

We'll also start appreciating the fact that this API stands at a lower level when compared to the Hubs API because its features are more basic, but at the same time we'll see that it's still a very useful, powerful, and easy-to-use API.