Garlic is widely used around the world for its pungent flavor as a seasoning or condiment. The garlic plant’s bulb is the most commonly used part of the plant. With the exception of the single clove types, garlic bulbs are normally divided into numerous fleshy sections called cloves. Garlic cloves are used for consumption (raw or cooked) or for medicinal purposes. They have a characteristic pungent, spicy flavor that mellows and sweetens considerably with cooking.
Other parts of the garlic plant are also edible. The leaves and flowers (bulbils) on the head (spathe) are sometimes eaten. They are milder in flavor than the bulbs, and are most often consumed while immature and still tender. Immature garlic is sometimes pulled, rather like a scallion, and sold as “green garlic”. When green garlic is allowed to grow past the “scallion” stage, but not permitted to fully mature, it may produce a garlic “round”, a bulb like a boiling onion, but not separated into cloves like a mature bulb. It imparts a garlic flavor and aroma in food, minus the spiciness. Green garlic is often chopped and stir-fried or cooked in soup or hotpot in Southeast Asian (i.e. Vietnamese, Thai, Lao, Cambodian, Singaporean) and Chinese cookery, and is very abundant and low-priced. Additionally, the immature flower stalks (scapes) of the hardneck and elephant types are sometimes marketed for uses similar to asparagus in stir-fries.
Reference.