Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. Cauliflower is an annual plant that reproduces by seed. Typically, only the white curd head of aborted floral meristems is eaten, while the stalk and surrounding thick, green leaves are used in vegetable broth or discarded.

Cauliflower's name is from Latin caulis (cabbage) and flower, an acknowledgment of its unusual place among a family of food plants which normally produces only leafy greens for eating. Brassica oleracea also includes cabbage, brussels sprouts, kale, broccoli and collard greens, though they are of different cultivar groups.

Cauliflower has a long history. François Pierre La Varenne employed chouxfleurs in Le cuisinier françois. They had been introduced to France from Genoa in the 16th century, and are featured in Olivier de Serres' Théâtre de l'agriculture (1600), as cauli-fiori "as the Italians call it, which are still rather rare in France; they hold an honorable place in the garden because of their delicacy," but they did not commonly appear on grand tables until the time of Louis XIV.