The National Guard and the other reserve forces comprise the reserve components of the United States Armed Forces. Reserve forces combine civilian life with part-time military service. All of the reserves are part of federally recognized branches of the military, though some are directly governed by states.
The seven reserves are the Army National Guard, the Army Reserve, the Navy Reserve, the Marine Corps Reserve, the Air National Guard, the Air Force Reserve and the Coast Guard Reserve. Although officially all reserves, the five branches aside from the Army and Air National Guard are sometimes referred to as just reserves.
The governor of each reserve's respective state acts as the commander-in-chief of the Army and Air National Guard. The Army, Air Force, Navy and Marine Reserves are auxiliary to their respective branches and are federal subordinates. Reserve forces are generally not called to full-time military service unless the country goes to war.