An innerspring mattress uses a steel coil support system. Manufacturers offer several different types of spring systems, including units with springs connected into a single unit and individually wrapped pocketed coils. Spring shapes, designs, coil gauge, and number of coils in a mattress can vary. The innerspring is covered by padding or upholstery materials, which can include various foams, fiber, and additional layers of smaller steel springs. Coil count can be more arbitrary, but the idea is that the greater the number of coils, the more points of support and greater distribution, thus the better the bed can contour and support the sleeper.