DayBed , Trundle Bed

Daybeds are used as beds as well as seating. They can be made out of wood, metal or a combination of wood and metal.
A cross between chaise longue, sofa and a bed.
Daybeds typically feature a back and sides and come in Twin Size (38" x 75"). Often daybeds will also feature a trundle to expand sleeping capacity.
Many of today's daybeds employ a linkspring as the support mechanism for a mattress. The linkspring is a rectangular metal frame (roughly the footprint of the mattress) with cross supports. A wire or polyester / nylon mesh held in place by a network of springs lays across the top of the linkspring. The linkspring design provides support and creates clearance underneath a daybed for storage.