A double-barrel shotgun is a type of firearm that features two parallel barrels, allowing the shooter to fire two shots in quick succession. These shotguns are commonly used for hunting game birds and clay shooting. They come in various gauges, with the most popular being 12-gauge and 20-gauge. Double-barrel shotguns can be classified into two main types: side-by-side and over-and-under. Side-by-side shotguns have barrels positioned next to each other, while over-and-under shotguns stack one barrel on top of the other. Both designs offer distinct advantages in terms of balance and aiming.