Allium sativum, commonly known as garlic, is a species in the onion family Alliaceae. Its close relatives include the onion, shallot, leek, and chive. Garlic has been used throughout recorded history for both culinary and medicinal purposes. It has a characteristic pungent, spicy flavor that mellows and sweetens considerably with cooking. A bulb of garlic, the most commonly used part of the plant, is divided into numerous fleshy sections called cloves. Single clove garlic (also called Pearl garlic or Solo garlic) also exists—it originates in the Yunnan province of China. The cloves are used as seed, for consumption (raw or cooked), and for medicinal purposes. The leaves, stems (scape), and flowers (bulbils) on the head (spathe) are also edible and are most often consumed while immature and still tender. The papery, protective layers of "skin" over various parts of the plant and the roots attached to the bulb are the only parts not considered palatable.

The ancestry of cultivated garlic, according to Zohary and Hopf, is not definitely established: "A difficulty in the identification of its wild progenitor is the sterility of the cultivars."

Allium sativum grows in the wild in areas where it has become naturalised; it probably descended from the species Allium longicuspis, which grows wild in southwestern Asia. The "wild garlic", "crow garlic", and "field garlic" of Britain are the species Allium ursinum, Allium vineale,...