Airsoft is primarily a recreational activity where replica firearms shooting plastic rounds are used for personal collection, gaming (similar to Paintball), or professional training purposes (Military Simulations, a.k.a. MilSim, and Police training exercises). A primary difference between airsoft firearms and BB guns is that airsoft uses 6mm or 8mm plastic pellets and have muzzle velocities of typically less than 180 metres per second (600 feet), which is generally considered safe when used in a controlled environment, whereas a BB gun utilizes metal ammunition and shoots at higher velocities (120-365+ MPS) (400-1200 feet), making them unsuitable for gaming and training purposes. Another distinguishing factor between BB guns and airsoft guns is that the latter generally uses hop-up (back-spin on the BB) to increase their effective range, since the lower muzzle velocity of these guns shortens their shooting distance.

Airsoft games vary greatly in style and composition depending on location, budget, and the quantity of participants but often range from short-term skirmishes and organized scenarios to military simulations and historical reenactments. Combat situations on the battlefield mainly involve the use of common military tactics to achieve the objectives set in each game. Participants typically use varying types of airsoft weaponry along with either real or replica military gear and uniforms.