Pottery is the ceramic material which makes up potterywares, of which major types include earthenware, stoneware and porcelain. The place where such wares are made is also called a pottery (plural "potteries"). Pottery also refers to the art or craft of a potter or the manufacture of pottery. A dictionary definition is simply objects of fired clays. The definition of pottery used by the American Society for Testing and Materials (ASTM) is "all fired ceramic wares that contain clay when formed, except technical, structural, and refractory products."