A bunk bed is a type sleeping bed in which one bed frame is stacked on top of another. There are several different types of bunk beds, with each type entirely dependent on the shape and structure of the bunk bed frame. The standard bunk bed frame is the most common type, having two same size mattresses. A twin over full bunk bed frame, on the other hand, is where the bottom mattress is a full size and the top one is a twin size. There's also a futon bunk bed frame where the lower bed is convertible into a Western-style futon couch when not being used as a bed. In an L-shape bunk the bottom bed is oriented at a right angle to the top bed such that when viewed from above the beds form an L. A loft bed denotes a bunk bed that has only the top bunk, creating an open space underneath that can be occupied by a chest, drawers, or even a work area. Bunk bed frames can be made of wood, metal, or a combination of both.
