Food provides nutrients and is obtained from plants and animals. Most food comes from cereal grains like wheat and rice that are fed to livestock. Some foods come from fungi or algae while others like salt are used to preserve foods. Plants and plant parts are also consumed, including seeds which are a source of nutrients and oils. Animals are used directly as meat or indirectly through products like milk, eggs and honey. Food production is increasingly focused on sustainability and food safety aims to prevent foodborne illness.