The United States Marine Corps (USMC), also referred to as the United States Marines or simply the Marines, is the naval infantry service branch of the United States Armed Forces. It is responsible for conducting expeditionary and amphibious warfare through combined arms, implementing its own infantry, artillery, aerial, and special operations forces. The U.S. Marine Corps is a part of the United States Department of Defense and is one of the six armed forces of the United States and one of the eight uniformed services of the United States.