Popcorn or popping corn's a type of corn, which explodes from the kernel and puffs up when heated. Corn popping was originally discovered by Native Americans, but became popular as a snack food during the United States Great Depression, especially in movie theatres. Corn's able to pop because, unlike other grains, its kernels have a hard moisture-sealed hull and a dense starchy filling. This allows pressure to build inside the kernel until an explosive "pop" results. Some strains of corn are n… (More on Popcorn)