You have several options while travelling. You can stay in hotels, motels, b&b's, youth hostels, guesthouses, inns, tents, caravans, your car or even sleep out in the open. Or you can stay in a Rotel! A rolling hotel.
This coach has space for twenty passengers and one driver. During the day you go and visit the sights of a certain area, during the night you could park almost anywhere and out comes the hotel part. Apart from the beds in the rear part of this coach, there's also a kitchen where meals can be prepared for all passengers. There's probably a toilet area as well, although I couldn't really find out where that would be supposed to go.
I have seen them out in Italy with the trailer which held many more people than this, but in my mind, it just looks like a lot of coffins one on top of each other and very uncomfortable. I know the Irish aren't too fond of them either. They don't add anything to the Irish economy, because they bring everything themselves, right up to their dinner. This one I saw in Saintes Maries de la Mer in Southern France.
I wonder where they stay during the night though...