Originally, the word "artillery" referred to any group of soldiers primarily armed with some form of manufactured weapon or armour. Since the introduction of gunpowder and cannon, "artillery" has largely meant cannon, and in contemporary usage, usually refers to shell-firing guns, howitzers, and mortars (collectively called barrel artillery, cannon artillery or gun artillery) and rocket artillery. In common speech, the word "artillery" is often used to refer to individual devices, along with their accessories and fittings, although these assemblages are more properly called "equipment". However, there is no generally recognized generic term for a gun, howitzer, mortar, and so forth: the United States uses "artillery piece", but most English-speaking armies use "gun" and "mortar". The projectiles fired are typically either "shot" (if solid) or "shell" (if not solid). Historically, variants of solid shot including canister, chain shot and grapeshot were also used. "Shell" is a widely used generic term for a projectile, which is a component of munitions.