Onion is the bulb of a vegetable plant. It is a species of biennial herbaceous plants of the Amaryllidaceae family (the large Alliaceae family). The onion is made up of white or pink, fleshy and juicy leaves, layered on top of one another. There are several varieties, some of which are particularly rich in antioxidants. The onion is an essential ingredient and is found in many culinary specialties and is used as a seasoning or as a vegetable. Whether raw, cooked, or fried, the onion is one of the most consumed vegetables in the world.