A main battery is the primary weapon or group of weapons around which a warship is designed. As such, a main battery was historically a naval gun or group of guns used in volleys, as in the broadsides of cannon on a ship of the line. Later, this came to be turreted groups of similar large-caliber naval rifles. With the evolution of technology the term has come to encompass guided missiles and torpedoes as a warship's principal offensive weaponry, deployed both on surface ships and submarines.
A main battery features common parts, munition and fire control system across the weapons which it comprises.