Food processing is the transformation of agricultural products into food, or of one form of food into other forms. Food processing includes many forms of processing foods, from grinding grain to make raw flour to home cooking to complex industrial methods used to make convenience foods. Early types of food processing included cooking, smoking, fermentation, and drying. These methods have been refined but are still in use today. New technologies have been developed, including irradiation, high-pressure, extrusion, and freeze-drying, that have generated new products and enhanced food safety and quality. Food processing means the ways that are used to change raw ingredients into food so that they can be eaten by humans or animals. It often takes clean, harvested or slaughtered and butchered components and uses these to produce attractive and marketable food products.