Beans are one of the longest-cultivated plants. Broad beans, also called fava beans, in their wild state the size of a small fingernail, were gathered in Afghanistan and the Himalayan foothills. In a form improved from naturally occurring types, they were grown in Thailand from the early seventh millennium BCE, predating ceramics. They were deposited with the dead in ancient Egypt. Not until the second millennium BCE did cultivated, large-seeded broad beans appear in the Aegean, Iberia and transalpine Europe. In the Iliad (8th century BCE) there is a passing mention of beans and chickpeas cast on the threshing floor.

Currently, the world gene banks hold about 40,000 bean varieties, although only a fraction are mass-produced for regular consumption.

Most of the foods we call "beans", "legumes", "lentils" and "pulses" belong to the same family, Fabaceae ("leguminous" plants), but are from different genera and species, native to different homelands and distributed worldwide depending on their adaptability. Many varieties are eaten both fresh (the whole pod, and the immature beans may or may not inside) or shelled (immature seeds, mature and fresh seeds, or mature and dried seeds). Numerous legumes look similar, and have become naturalized in locations across the world, which often lead to similar names for different species.