A castor refers to a wheel or set of wheels mounted on a swivel or fixed plate, often attached to the legs of furniture pieces such as chairs, tables, or cabinets. Castors allow for ease of movement and are typically used to facilitate the mobility of furniture within a space. They can be made of various materials such as metal, plastic, or rubber and come in different sizes and designs depending on the specific furniture application. Small roller attached to the feet or base of a piece of furniture, for ease in moving around. Today they are made of rubber or synthetic materials.