A bun is a small, usually sweet, bread. Commonly they are hand-sized or smaller, domed in shape, with a flat bottom. A bun can also be a savory bread roll similar to a bap or barmcake.
Basic buns are usually made using flour, sugar, milk, yeast, cardamom, and butter.
"Bun" can also refer to a kind of filled dumpling, as Chinese baozi and the Lutonian Halapchi.
A bun can be long and skinny, short and round, and or come in many different shapes and sizes.