Broccoli is an edible green plant in the cabbage family whose large flowering head, stalk and small associated leaves are eaten as a vegetable. Broccoli is classified in the Italica cultivar group of the species Brassica oleracea. Broccoli has large flower heads, or florets, usually dark green, arranged in a tree-like structure branching out from a thick stalk, which is usually light green. The mass of flower heads is surrounded by leaves. Broccoli resembles cauliflower, which is a different but closely related cultivar group of the same Brassica species.

Cabbage, comprising several cultivars of Brassica oleracea, is a leafy green, red (purple), or white biennial plant grown as an annual vegetable crop for its dense-leaved heads. It is descended from the wild cabbage, and belongs to the "cole crops" or brassicas, meaning it is closely related to broccoli and cauliflower ; Brussels sprouts ; and Savoy cabbage.