A banana is a herb, in the genus Musa, which because of its size and structure, is often mistaken for a tree. It is cultivated for its fruit, which bears the same name. Bananas are of the family Musaceae and closely related to plantains. Globally, bananas rank fourth after rice, wheat and maize in human consumption; they are grown in 130 countries worldwide, more than for any other fruit crop. Bananas are native to tropical southeastern Asia.

The main or upright growth is called a pseudostem, which, when mature, will obtain a height of 2–8 m (varies by cultivar), with leaves of up to 3.5 m in length. Each pseudostem produces a single bunch of bananas, before dying and being replaced by a new pseudostem. The base of the plant is a rhizome (known as a corm). Corms are perennial, with a productive lifespan of 15 years or more.

The term banana is applied to both the plant and its elongated fruit (technically a false berry) which grow in hanging clusters, with up to 20 fruit to a tier (called a hand), and 5-20 tiers to a bunch. The total of the hanging clusters is known as a bunch, or commercially as a "banana stem", and can weigh from 30–50 kg. The fruit averages 125g, of which approximately 75% is water and 25% dry matter content. Bananas are a valuable source of Vitamin A, Vitamin C, and potassium.