Popcorn (also called popped corn, popcorns, or pop-corn) is a variety of corn kernel which expands and puffs up when heated. It is one of the oldest snacks, with evidence of popcorn dating back thousands of years in the Americas. It is commonly eaten salted, sweetened, or with artificial flavorings. Some strains of corn (taxonomized as Zea mays) are cultivated specifically as popping corns. The Zea mays variety everta, a special kind of flint corn, is the most common of these. Popcorn is one of six major types of corn, which includes dent corn, flint corn, pod corn, flour corn, and sweet corn.

Source: Wikipedia