Bonell coils are the oldest and most common type of coil. First adapted from buggy-seat springs of the 19th Century and still prevalent in less expensive mattresses.These coils are hourglass-shaped and the ends of the wire are knotted or wrapped around the top and bottom circular portion of the coil and then self-tied. Although this coil offers decent support, it does not have the ability to conform to the body as well as other types.

Pocket coils are individually wrapped in a fabric encasement and are usually tempered, or in the case of the Simmons Beautyrest, carbon magnesium is added. Some manufacturers pre-compress these coils, making the mattress firmer and less likely to transfer motion.

Off-set coils are designed to hinge, thus conforming to a persons body shape. These coils are very sturdy, and they have stable innersprings that provide great support.

Continuous coils have a hinging effect, similiar to offset coils. They are excellent in distributing body weight and limiting motion transfer.

Air Mattresses use an air chamber instead of springs to provide support.

Foam mattresses use latex foam or memory foam instead of springs to provide support. Since foam varies in quality, prices can vary widely. Today, more and more people are switching to "healthy" alternatives such as latex foam in addition to memory foam, both providing a hypo-allergix sleeping surface that is also mold/mildew resistant, while also instantly responding to touch and temperature.

Foundations -- Three main types

1. Boxsprings consist of a rigid frame which contains extra-heavy duty springs. This type of foundation can contribute to a softer, bouncier mattress while maintaining support.
2. Traditional wood foundations are usually made of soft woods such as pine, or hardwoods such as poplar. They usually consist of seven or eight support slats covered with cardboard or beaverboard. Often referred to as a zero deflection unit because it increases firmness and stability.
3. Grid foundations are a combo of wood and steel.

1. The insulator seperates the mattress core from the middle upholstery. It is usually made of fiber or mesh and is intended to keep the middle upholstery in place.
2. The middle upholstery comprises all the material between the insulator and the quilt. It is usually made from materials which are intended to provide comfort to the sleeper, including regular foam, viscoelastic foam, felt, polyester fibers, cotton fibers, convoluted (eggcrate) foam, and non-woven fiber pads.
3. The quilt is the top layer of the mattress. Made from light foam or fibers stitched to the underside of the ticking, it provides a soft surface texture to the mattress and can be found in varying degress of firmness.