Popcorn is the puffed snack made from Zea mays everta, the one type of maize whose small, hard-shelled kernels explode into light, crisp, flower-shaped flakes when heated. Unlike sweet corn (eaten fresh) or dent corn (milled into meal), popcorn is grown to be dried on the cob and popped whole — a whole-grain snack that is nutty and toasty when plain, and the canvas for everything from salt and melted butter to caramel, cheese and chili. Cheap, fast, gluten-free and nearly all bran-and-germ intact, it is one of the most widely eaten snack foods on earth and the defining smell of the cinema.