A box spring is a type of bed base designed to support a mattress. It typically consists of a wooden frame covered in fabric, with springs or a solid platform inside. Box springs help absorb shock and provide additional height to the bed, making it easier to get in and out of. Box springs are often used with innerspring mattresses, but they can also work with other types like memory foam or latex mattresses. They are available in various sizes to match standard mattress dimensions, such as twin, full, queen, and king.