The AR-15 is a lightweight, air-cooled, magazine fed, autoloading, centerfire shoulder-fired rifle. The original ArmaLite/Colt AR-15 was a selective-fire prototype submitted for consideration as a military infantry rifle, which was later adopted as the M16, and is distinguished from later civilian-model AR-15 rifles marketed by Colt Firearms. Currently, AR-15 is a generic term for a civilian semi-automatic rifle similar to the military M16/M4-type weapons.