An air gun is a type of firearm that uses compressed air or gas to propel projectiles, typically pellets or BBs. Unlike traditional firearms that use gunpowder, air guns are quieter and often used for target shooting, pest control, and small game hunting. They come in various types, including pneumatic, spring-powered, and CO2-powered models. Air guns are popular for recreational shooting and training due to their lower cost and reduced recoil. They are often categorized by their caliber, with common sizes being .177 and .22. Safety is important when using air guns, as they can still cause injury if misused.