Food that's been heated before it's eaten or served is cooked. Your grandmother might insist on everyone eating a hot, cooked breakfast before they do anything else.
A cooked turkey is the centerpiece of many Thanksgiving feasts, while you might prefer raw carrots to cooked carrots. Cooked food has been baked, roasted, fried, broiled, or sauteed. If someone tells you, "Your goose is cooked," she means that you're in big trouble, or that you're stuck in an impossible situation. This phrase was first used in the mid-1800s, but its origin is uncertain.