A squad automatic weapon (SAW, also known as section automatic weapon or light support weapon) is a weapon used to give infantry squads or sections a portable source of automatic firepower. Weapons used in this role are often selective fire rifles, usually fitted with a bipod and heavier barrel to perform as light machine guns. Squad automatic weapons usually fire the same cartridge as the assault rifles or battle rifles carried by other members of the unit. This reduces logistical requirements by making it necessary to supply only one type of ammunition to a unit. Squad automatic weapons are light enough to be operated by one person, as opposed to heavy machine guns such as the M2 Browning, which fire more powerful cartridges but require a crew to operate at full effectiveness.