A futon is a traditional Japanese style of bedding. A complete futon set consists of a mattress and a duvet. Both elements of a futon bedding set are pliable enough to be folded and stored away in a large closet during the day. This allows a room to serve as a bedroom at night, but serve other purposes during the day. Traditionally, futons are used on tatami, a type of mat used as a flooring material. It also provides a softer base than wooden or stone floors. More at Wikipedia