Futon Bed
The futon bed originated in Japan. However, traditionally, these items were nothing more than a mattress that was spread out on the floor for sleeping. And in most cases the mattress was only a few inches thick.
A Western futon bed is different in that it uses a frame that can be set up as either a bed or a sofa. They are often used by people that either do not have enough room for multiple pieces of furniture, or by those that prefer a minimalist aesthetic. The mattresses used for these futons are usually much thicker than the traditional models.
A futon bed can also come in a platform configuration. These pieces of furniture are designed to be used as beds only, as they do not fold. The mattress is simply laid on the platform, much like a traditional bed.