A ball mill is a type of grinder used to grind materials into extremely fine powder for use in mineral dressing processes, paints, pyrotechnics, ceramics, and selective laser sintering. It works on the principle of impact and attrition: size reduction is done by impact as the balls drop from near the top of the shell. There are many synonyms for the term "ball mill," including pebble mill, tumbling mill, and stirred mill. Each of these terms refers to a slightly different type of ball mill, but all of them are designed to grind material to a fine powder. Whether used in a laboratory or in a production environment, ball mills are an essential tool for processing a variety of materials.