A box spring is a support for a mattress that is manufactured to be the same size as the bed. It consists of a wooden frame filled with springs or a metal grid and wrapped in fabric. The primary function of a box spring is to provide underlying support for the mattress and absorb impact, reducing the wear and tear on the mattress. It also helps to increase the height of the bed, making it easier to get in and out of bed. Box springs were originally designed for innerspring mattresses, but today, most modern mattresses do not necessarily require a box spring. Memory foam and latex mattresses, for example, could be better suited to a platform bed that uses wooden slats for support. However, some bed frames, like a metal rail bed frame, require using a box spring to keep the mattress from sagging between rails. Skipping the box spring altogether or going with a low-profile, thinner alternative can give your bed a sleeker design without sacrificing any support that a traditional box spring would provide.