Cheese is a generic term for a diverse group of milk-based food products made mostly from the milk of cows but also other mammals, including sheep, goats, buffalo, reindeer, camels and yaks. It is produced by coagulation of the milk protein casein. Cheese is produced in wide-ranging flavors, textures, and forms. Hundreds of types of cheese are produced. Their styles, textures and flavors depend on the origin of the milk (including the animal's diet), whether they have been pasteurized, the butterfat content, the bacteria and mold, the processing, and aging.