Flooring is the general term for a permanent covering of a floor, or for the work of installing such a floor covering. Floor covering is a term to generically describe any finish material applied over a floor structure to provide a walking surface. Both terms are used interchangeably but floor covering refers more to loose-laid materials.Materials almost always classified as flooring include carpet, laminate, tile and vinyl.The floor under the flooring is called the subfloor, which provides the support for the flooring. Special purpose subfloors like floating floors, raised floors or sprung floors may be laid upon another underlying subfloor which provides the structural strength. Subfloors that are below grade (underground) or ground level floors in buildings without basements typically have a concrete subfloor. Subfloors above grade (above ground) typically have a plywood subfloor.The choice of material for floor covering is affected by factors such as cost, endurance, noise insulation, comfort and cleaning effort. Some types of flooring must not be installed below grade, including laminate and hardwood due to potential damage from moisture.The sub-floor may be finished in a way that makes it usable without any extra work, see: -Earthen floor adobe or clay floors-Solid ground floor, cementitious levelling/wearing/granolithic screeds, [1] polymer-modified concretes and levelling/wearing screeds.[2]CarpetingCarpet is a soft floor covering made of bound carpet fibers or stapled fibers. Carpeting refers to wall-to-wall coverage, whereas a rug is simply used to cover a space. This type of flooring is typically used indoors and can be used in both high and low traffic areas. It typically lasts for 15-18 years before it needs to be replaced. The quality of a carpet is usually measured in face weight, or how many fibers there are per square inch. The higher the face weight the more plush a carpet will feel.Carpets come in a variety of materials including wool, nylon, olefin and polyester.There are different types of carpet like twists, which is commonly referred to as a berber. Twist carpeting is composed of multiple twisted fibers set into the carpet backing. It is typically used in low traffic areas. Another type of carpeting is looped carpets, which are composed of looped fibers set into the carpet backing. This type of carpeting is typically used in high traffic areas as it is easy to clean.Carpet paddingPadding can be placed underneath the carpet to add comfort and provide some noise insulation. The level of comfort is determined by the type of material used, which can include memory foam and rubber regrind.Wood flooringMany different species of wood are fabricated into wood flooring in two primary forms: plank and parquet. Hardwoods are typically much more durable than softwoods. Reclaimed lumber has a unique appearance and is used in green (environmentally responsible) building.Engineered hardwood has a thin solid wood layer on top with a composite core. It can be a less expensive option than buying hardwood, but it cannot be sanded and refinished. This flooring typically is installed with a click-lock method.Bamboo flooring is a floor manufactured from the bamboo plant and is a type of hardwood flooring, though technically not a wood. Bamboo is known to be durable and environmentally friendly. It is available in many different patterns, colors, and textures.Cork flooring is a flooring material manufactured from the by-product of the cork oak tree. Cork floors are considered to be eco-friendly since the cork oak tree bark is stripped every nine to ten years and doesn't damage the tree. Cork flooring comes in both tiles and planks, and can have glue or glues-less installation.