Barley is a versatile, ancient cereal grain from the grass family, cultivated worldwide for its nutritional value, as animal feed, and for making malt for beverages like beer and whiskey. It is eaten as a whole grain, ground into flour for baking, and used in foods like soups, stews, and breakfast cereals. Barley is a source of fiber and essential nutrients, but it contains gluten, making it unsuitable for people with celiac disease.