A bed (About this sound listen ) is a piece of furniture used as a location to sleep or relax. It has a secondary use as a place to engage in sexual relations.Most modern beds consist of a soft mattress on a bed frame, with the mattress resting either on a solid base, often wooden slats, or a sprung base. In North America many beds include a box spring inner-sprung base, a large mattress-sized box containing wood and springs that provide additional support and suspension for the mattress.