Cauliflower is a cultivar within the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed. Typically, only the head (the white curd) is eaten while the stalk and surrounding thick, green leaves are discarded. Cauliflower is very nutritious, and may be eaten cooked, raw or pickled. Its name is a variation of cole flower or kale flower (cole and kale being variations of the same word), an acknowledgment of its unusual place among a family of food plants which normally produces only leafy greens for eating. The Brassica oleracea species is the same species as cabbage, brussels sprouts, kale, broccoli and collard greens, though they are of different cultivar groups.Cauliflower is low in fat, high in dietary fiber, folate, water and vitamin C, possessing a very high nutritional density. Traces of almost all the B vitamins, calcium, iron, magnesium, phosphorous, potassium and zinc are to be found in this highly charged vegetable.

As a member of the brassica family, cauliflower shares with broccoli and cabbage several phytochemicals which are beneficial to human health, including sulforaphane, an anti-cancer compound released when cauliflower is chopped or chewed. In addition, the compound indole-3-carbinol, which appears to work as an anti-estrogen, appears to slow or prevent the growth of tumors of the breast and prostate. Cauliflower also contains substances which may improve the liver's ability to detoxify carcinogenic substances. A high intake of cauliflower has been found to reduce the risk of aggressive prostate cancer