Airsoft refers to a class of replica air powered guns that originated from Japan (although the origins go back to the US in the 70s). The power levels are way below those of traditional airguns, but the guns are 1:1 scale copies of original pistols, rather than original designs.
Airsoft is primarily a recreational activity with replica firearms that shoot plastic BBs that are often used for personal collection, gaming (similar to paintball), or professional training purposes (military simulations, a.k.a. MilSim, and police training exercises).
A modern combat sport in which participants eliminate their opponents by hitting them with spherical non-metallic pellets launched from a compressed-air gun
a marksman who shoots at people from a concealed place
A sniper is a highly trained marksman who shoots targets from concealed positions or distances exceeding the capabilities of regular personnel. Snipers typically have specialized training and distinct high-precision rifles.
Sniper is a 1993 action film starring Tom Berenger and Billy Zane as American snipers on an assassination mission in Panama.