The moern torpedo (historically called an automotive, automobile, locomotive, or fish torpedo) is a self-propelled explosive projectile weapon, launched above or below the water surface, propelled underwater toward a target, and designed to detonate on contact or in proximity to a target. The original use of "torpedo" was for a variety of devices that would today be mostly called a "mine". However, from the First World War onwards "torpedo" was only used for an underwater self-propelled missile, often called colloquially a "fish".