Green beans are young, unripe fruits of various cultivars of the common bean, although immature or young pods of the runner bean, yardlong bean, and hyacinth bean are used in a similar way. Green beans are known by many common names, including French beans, string beans, and snap beans or simply "snaps." In the Philippines, they are also known as "Baguio beans" or "habichuelas" to distinguish them from yardlong beans.

Phaseolus vulgaris, the common bean, is a herbaceous annual plant grown worldwide for its edible dry seeds or green, unripe pods. Its leaf is also occasionally used as a vegetable and the straw as fodder. Its botanical classification, along with other Phaseolus species, is as a member of the legume family Fabaceae. Like most members of this family, common beans acquire the nitrogen they require through an association with rhizobia, which are nitrogen-fixing bacteria.