A communication process is usually needs at least two parts. In order these parts to communicate, they have to speak and listen to others. In networks we use to call what speaks a client, and that listens a server. In reality, like in real life, when two parts communicate, they act both as a server and as a client, while both listen and speak in order to talk. So here, now, we're gonna call me from this host as the server, and the device you use as the client.