Action of arriving and registering in a hotel is called check in. There are various formalities, which are involved with check in procedures i.e. allocating a room, taking guest's name, asking the guest to sign the hotel register whereas action of leaving and paying the bill after a stay in a hotel is called check out process. The formalities, which are involved with check out process, are presenting the bill and making sure it is paid, taking the room key, etc.