Alexander Calder was an American sculptor and artist who is best known for his invention of the MOBILE and STABILE sculptures. A 'STABILE' is a type of sculpture that is stationary, while a 'MOBILE' is a type of sculpture that is composed of several parts that move in response to air currents. Calder's most famous works are his mobiles and stabiles, which are often made from wire, sheet metal, and other found objects. The term 'Calder Creation' is used to refer to any of his sculptures, both mobiles and stabiles.