BBs are small, round pellets typically made of plastic or metal, often used in airsoft guns and BB guns. They are designed for recreational shooting and are usually 4.5 mm in diameter. BBs can be used for target practice, competitions, or casual play, and they come in various weights and materials to suit different types of air guns. The term "BB" originally referred to a specific size of lead shot used in shotgun shells. Over time, it has evolved to describe these small projectiles used in airsoft and BB guns. Safety gear, such as goggles, is recommended when using BBs to prevent eye injuries.