Cauliflower is one of several vegetables in the species Brassica oleracea, in the family Brassicaceae. It is an annual plant that reproduces by seed. Typically, only the head is eaten. Cauliflower heads resemble those in broccoli, which differs in having flower buds.

There are hundreds of historic and current commercial varieties used around the world. White cauliflower is the most common color of cauliflower.