Barley is a cereal of Gramineae family.
From archeological finds, we know that Barley was already cultivated about 8000 b.c. It has been used, besides human nutrition, also as animal fodder, or as a source of fermentable material for alcoholic beverages.
In cooking, Barley meal, can be used, combined with water or milk, to make a beverage, sometimes as a healthier alternative to coffee. Pearl barley (or pearled barley) can be boiled and used like rice or pasta.
Fun fact: Barley was used by ancient Egyptians to make unleavened bread. Pliny the Elder, in one of its works, wrote that gladiators, armed combatant of arenas of ancient Rome, used to be call “hordeani” (from “hordeum”, latin for Barley) because their staple food was precisely Barley, usually cooked as a soup, as it was considered as a great energy source. And that’s absolutely true, as per 100 gr, it has 350 kcal!