[Relic?]

Yes, that's the communicator, or comm for short. It let's us keep in touch with the other passengers on board the ship. Here, let me see...

[She takes his and turns it so it's facing him again, pointing out some of the more important buttons]

This is the call button, what you would use to get in contact with someone. This is talk, to respond to a message; this is text, which is... sort of like mail, but much, much quicker. It's a bit tricky at first, but once you get used to it you should be ok.