Onions (Allium cepa) are bulb-shaped vegetables that grow underground.

Also known as bulb onions or common onions, they are grown worldwide and closely related to chives, garlic, scallions, shallots, and leeks.

Onions may have several health benefits, mostly due to their high content of antioxidants and sulfur-containing compounds.

They have antioxidant and anti-inflammatory effects and have been linked to a reduced risk of cancer, lower blood sugar levels, and improved bone health.

Commonly used as a flavoring or side dish, onions are a staple food in many cuisines. They can be baked, boiled, grilled, fried, roasted, sautéed, powdered, or eaten raw.

Onions vary in size, shape, and color, but the most common types are white, yellow, and red. The taste ranges from mild and sweet to sharp and spicy, depending on the variety and season.

Onions can also be consumed when immature, before the bulb reaches full size. They are then called scallions, spring onions, or summer onions.

This article tells you everything you need to know about onions.