A rug is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but, since the 20th century, synthetic fibers such as polypropylene, nylon or polyester are often used, as these fibers are less expensive than wool. The pile usually consists of twisted tufts which are typically heat-treated to maintain their structure. The term "rug" is often used interchangeably with the term "carpet", although the term "carpet" can be applied to a floor covering that covers an entire house, whereas a "rug" is generally no bigger than a single room, and traditionally does not even span from one wall to another, and is typically not even attached as part of the floor.
Area Rugs can be produced on a loom quite similar to woven fabric, made using needle felts, knotted by hand (in oriental rugs), made with their pile injected into a backing material (called tufting), flatwoven, made by hooking wool or cotton through the meshes of a sturdy fabric or embroidered. Carpet is commonly made in widths of 12 feet (3.7 m) and 15 feet (4.6 m) in the USA, 4 m and 5 m in Europe. Since the 20th century, where necessary for wall-to-wall carpet, different widths of carpet can be seamed together with a seaming iron and seam tape (formerly it was sewn together) and fixed to a floor over a cushioned underlay (pad) using nails, tack strips (known in the UK as gripper rods), adhesives, or occasionally decorative metal stair rods. Wall-to-wall carpet is distinguished from rugs or mats, which are loose-laid floor coverings, as wall-to-wall carpet is fixed to the floor and covers a much larger area.