Air Beds: These beds use a bladder of air to provide support.  New technology in bed design uses one bladder for each side of the bed surrounded by a track of foam to hold it in place.  This allows each partner to set their own level of firmness which is the primary advantage of this type of mattress.  Couples may find that getting cozy in the middle of the bed is uncomfortable due to the foam track or if partners have widely varying firmness preferences.  Noisy pumps and maintenance requirements can also be issues with this type of mattress.

Bed Frame:   A metal or wood frame with legs used to support a mattress and foundation with the ability to attach headboard/footboard.  Generally available in two heights:  conventional (7 ¼”) and low-profile (5 1/4”).  All queen and king size sets require a frame that is either metal with a center support bar and vertical center leg or on a headboard/footboard system, a minimum of 5 slats (1” x 6”) with a vertical center support.

Box Pillow Top:   Generally considered the most luxurious of the pillow top style, the “pillow” of these mattresses is thicker and typically made of high quality foam rather than fiber.

Box Spring: A box spring is designed to support an innerspring mattress by distributing weight and acting as a shock absorber.  A mattress and box spring together comprise a sleep set and both experience share in the wear and tear over time.

Cable Coil:  Coils made of 3 high carbon steel strands.  Inspired by the cable bridges, like the Golden Gate Bridge, these extremely durable coils are typically found in higher end beds.

California King: A bed that measures 72 inches wide and 84 inches long.

Coil Count :  The number of coils in an innerspring unit. A high coil count alone does not indicate better quality. Firmness support and durability are determined by the design of the coil, the gauge of wire used and the way the coil is engineered. The count is usually based on the number of coils in a full-size unit.

Coil on Coil:   Two 3 ½” coils are stacked on top of each other.  These coils have the least motion transfer and are extremely durable. 

Comfort System:   The upholstery and quilting layers of the mattress, generally consisting of a combination of materials (foams and fibers).   Comfort levels are generally determined by the type of materials and number of inches of cushioning provided.

Continuous Coil: An innerspring mattress coil configuration where each row of coils is made from a single piece of wire.

Convoluted Foam:   A.k.a. "egg-crate" foam is specially cut to produce hills and valleys, giving gentle softness and more surface comfort.

Corner Guards: Plastic or metal fittings secured to foundation corners to prevent material damage from the bed frame.

Density: The weight per cubic foot of foam. Density is independent of firmness but is an important indicator of foam quality as it affects durability and support. Generally, the greater the density, the better the foam will retain its original properties.

Double Bed: Also known as a full or regular size, a double bed measures 54 inches wide by 74 inches long.

Dust Mites: Microscopic arachnids (the same family as spiders, and ticks) that feed on dead skin that sloughs from our bodies. They live in mattresses, pillows, and bedroom carpets. Dust mites they cannot survive in natural latex and don’t do well in memory foam, but thrive in cotton, wool and polyester. People allergic to dust mites will show symptoms like rashes or nasal congestion.  

Edge Support:    A special design where the coils on the outer edge of an innerspring unit are positioned to give support right up to the edge of the bed.

Euro Top :  In this type of mattress, the edges of the pillow top are stitched down.  Some sleepers feel they “lose” width of the bed when the edges are sewn down.

Fatigue : A softening or loss of load bearing capacity of a mattress over time.  A mattress showing signs of fatigue is generally considered “worn out” and ready for replacement.

Foam : Polyurethane foam is used as padding material in comfort system of an innerspring mattresses. Foams come in a variety of densities and qualities and serve different purposes within the mattress.  See also Visco and Latex foams.

Foundation: A base or support for a mattress.  May be used as a generic term for box spring.

Gauge: The thickness measure of the wire used in innerspring mattresses. A lower gauge number denotes a heavier wire.   Coils made of lower gauges are stiffer (for example 13 gauge), giving the sleeper extra firmness.  Higher gauge wires are springier (15 gauge).  A quality bed will be equally durable regardless of which gauge you choose. 

Hammocking: An undesirable trait that signals it’s time for a new mattress. When weight is placed in the center, the corners tend to rise and bow in response to deep compression much like a hammock. May also be called "dishing" and "sagging".

High Contour Mattress: Measures 9" - 13" thick. Standard mattresses will measure under 9".

ILD: Indentation Load Deflection (ILD) is a measurement of foam firmness. Firmness is independent of foam density, although it is often thought that higher density foams are firmer. It is possible to have high density foams that are soft – or low density foams that are firm, depending on the ILD specification. ILD specification relates to comfort. It is a measurement of the surface feel of the foam. ILD is measured by indenting (compressing) a foam sample 25 percent of its original height. The amount of force (in pounds) required to indent the foam is its 25 percent ILD measurement. The more force required, the firmer the foam. Flexible foam ILD measurements range from 10 pounds (supersoft) to about 80 pounds (very firm).

King:   A bed that measures 76" wide by 80" long.

Latex Foam:   A natural foam product often used in the construction of premium latex foam mattresses.  This type of foam is often considered “cushier” than other foams.  Latex is also anti-microbial and is provides a very unfriendly environment for dust mites.

Memory Foam: A common name for visco-elastic foam. Temperature sensitive, slow recovery urethane foam that conform to the body and distributes pressure according to body heat and weight. It comes in many thicknesses, densities, and different levels of softness and firmness.  Visco foam may be used as the primary construction material, or as a component of the comfort system of an innerspring mattress.  An additional benefit of memory foams is that they are dust mite resistant.

No-Turn / No-Flip Mattress:  These are specific models have been designed to provide continuous support without the need to turn them over and use the reverse side of the mattress.  All Simmons and Sealy mattresses, and most Serta, are now made this way.  Mattresses without this design will required flipping and turning the mattress in order to keep from voiding the warranty.

Pillow Top Mattress: A top finishing treatment where additional cushioning materials is sewn over the entire surface of the mattress, giving the appearance of a large pillow. A pillow top mattress will be just as firm as it’s tight top counterpart, but will have a more plush, cushy feel.

Platform Bed: A wooden bed frame with slats that go across from side to side. With a  platform bed, you don’t need a box spring or a foundation because you can place the mattress directly on the slats.  This typically gives the platform bed a lower profile.

Pocket Coils: Cylindrical innerspring mattress coils, enclosed in separate flexible fabric pockets. The pockets are attached to adjacent pockets.

Pressure Points:   Places on the body where capillaries will close due to pressure against that area.  When in bed, these pressure points are typically the shoulders and hips. The result may be pain, numbness or morning stiffness.  A pressure relief mattress will have more give in this pressure points.

Prorated Warranty:   If a manufacturing defect occurs under a prorated warranty, the consumer will be required to pay a portion of the original retail price to have it replaced.  The amount they will have to pay is based on the amount of time that has passed since the original purchase.

Quilting:   The stitching used on the top of the mattress to hold the cover in place.  The style and amount of quilting will impact how firm or plush a mattress feels.  The more stitching, the firmer the feel.  Stitching that allows the cushioning to fluff up will feel more plush. 
Recovery Time:  The length of time it takes for a piece of foam to return to its original shape. Latex foam has a fast recovery time, and memory foam has a long recovery time. Along with ILD, the Recovery Time is one of the most important factors in determining comfort.  

Resiliency: Ability of a mattress to spring back to it’s original shape when pressure is released.

Split Queen Box: Some manufacturers are now splitting the box spring in two to allow for better maneuverability in tight spaces such as stairwells or narrow hallways.  Each box measures 30” by 80”.

Spring Mattresses: The most common type of mattress, this design derives it’s flexibility from a series of coiled wires surrounded by layers of padding. 

Ticking:   Ticking is the outer fabric covering on a mattress and foundation set.  Ticking can be made from a variety of fabrics, including polyester, cotton, silk, suede, cashmere or blends.

Tight Top : A mattress that does not have the extra ‘pillow’ of fabric on top.  Don’t let the name fool you, a mattress can be plush and feel very luxurious in a tight top.

Twin :  A bed that measures 39 inches wide by 75 inches long.

Visco Foam: Also known as "memory foam." Temperature sensitive, slow recovery urethane foam that conform to the body and distributes pressure according to body heat and weight. Not all memory foams are created equal, but come in come in a variety of thicknesses, densities, and different levels of softness and firmness.  Visco foam may be used as the primary construction material, or as a component of the comfort system of an innerspring mattress.

Warranty : A commitment by the manufacturer that your mattress will retain certain qualities over a specific period of time that also spells out what they will do if mattress does not live up to this commitment.  Warranties may be prorated, meaning that depending on how long you’ve owned the mattress you may bear part of the cost of replacement, or full (non-prorated), meaning that the manufacturer will replace the entire mattress.  As you compare mattresses, take the time to read through the warranty for each manufacturer.