‘Lift’is British English. ‘Elevator’ is American English.

You check in when you arrive at the hotel. You check out when you leave.

bill - a piece of paper which shows you how much you have to pay. receipt - a piece of paper which shows what you bought and how much you paid

A key is a specially-shaped piece of metal. A keycard is an electronic device in the shape of a card

Full board means that the hotel provides all your meals as well as your room. Half board includes breakfast and either lunch or supper.

A double room is a room for two people, with either two beds or one large bed suitable for two people. A twin-bedded room has two separate beds.