This means that you will rent a boat without a skipper and/or crew. This is your option if you have your skipper licence and you feel the confidence to rent the boat on your own. In that case, usually, yacht owners will ask you for the licence which proves your experience. You will manage the supplies for the trip, meals and organize your route.
The biggest advantage of chartering a bareboat is your independence to be alone with your own friends or family and choose your own route and schedule.