In it's typical configuration
the bunk bed
is actually multiple bed
s, one arranged over the other, used where the people to floor space ratio
is too high for more than one bed. Military
applications usually involve more than 2 beds, such as the five person cots-on-a-chain on the USS Alabama
, or the three person beds in a cabinet on WWII submarines.
In the suburbs however, the bunk bed is the source of many prepubescent hijinks, and can make a really cool fort.