Pocket spring (coil) mattresses are made with individual spring units (coils) rather than the orthopedic interconnected ones. The more springs there are in a coil mattress, the better it is able to support and adapt to contours of the human body and the differing shapes and masses of the torso and limbs. This kind of mattress provides firmness, but also controlled compression where needed. This mattress flexibility allows the mattress to respond to the precise shape, weight, size and sleeping patterns of any typical body during sleep.