This illustration shows a diagram of the application when a new user connects.
It is composed of three elements: a server, a new client, and three clients that are assumed to be already connected to the server.
The steps of the diagram are:
1. The new client asks the user for his or her user name.
2. The new client displays the chat interface.
3. The new client connects to the server using WebSocket.
4. The server pushes all the messages (old) to the new client.