Firearm

A firearm is device, typically used as a weapon, which fires projectile(s) with the force of the expanding gases created by the rapid burning of a confined propellant (typically gunpowder). Such weapons can be as small as handguns, which can be carried and used in one hand, or as large as the cannon on a battleship.

Such weapons are typically referred to as "guns" in common usage. Gun has a particular meaning in specialist usage, however, when referring to larger weapons; a gun is a direct-fire weapon (which fires directly at the target), whereas a howitzer or mortar is an indirect-fire weapon (a weapon that fires in a high arc to drop its fire down on a target).

see also Naval guns