A fighter aircraft is a military aircraft esigned primarily for attacking other aircraft, as opposed to a bomber, which is designed primarily to attack ground targets by dropping bombs. Fighters are comparatively small, fast, and maneuverable. Fighter aircraft are the primary means by which armed forces gain air superiority. At least since World War II, air superiority has been a crucial component of victory in most modern warfare, particularly conventional warfare between regular armies (as opposed to guerrilla warfare), and fighters' acquisition and maintenance represent a very substantial proportion of military budgets in modern militaries.