Floor covering, material made from textiles, felts, resins, rubber, or other natural or man-made substances applied or fastened to, or laid upon, the level base surface of a room to provide comfort, durability, safety, and decoration. Such materials include both handmade and machine-made rugs and carpets and smooth-surfaced floor coverings. Although the words carpet and rug are frequently used interchangeably in referring to textile floor coverings, in modern usage carpets are fastened to the floor and usually cover an entire floor area, and rugs are not fastened and rarely cover the entire floor. Carpets and rugs may be classified as handmade or machine-made. Smooth-surfaced coverings generally adhere to a subfloor and are manufactured as sheet goods or tiles.