A
bunk bed is a type of
bed in which one
bed frame is stacked on top of another. No box spring is required as the mattress lies on a flat surface, the bunkie (or bunky) board, and may be surrounded by rails. The nature of bunk beds allows two or more people to sleep in the same room while maximizing available floor space for activities. This leads to them being used in places with limited floor space, such as on
ships and in army
garrisons or in places where floorspace needs to be maximized, such as
dormitories,
summer camp cabins,
hostels,
children's rooms,
prison cells, or university
residence halls.