"The Army, Marine Corps, Navy, Air Force and Coast Guard are the armed forces of the United States. The Army National Guard and the Air National Guard are reserve components of their services and operate in part under state authority."
Army: "The largest and oldest service in the U.S. military, the Army provides the ground forces that protect the United States."
Marine Corps: "Marines are trained and equipped to answer threats all over the world because our Nation has interests beyond the borders of the United States. The USMC functions as a unique force, combining ground, aviation and amphibious assets to defend our country and its interests. From joint training that reinforces our relationships with allied countries to anti-terrorism missions to secure key ports, Marines are prepared to win, wherever the battle takes them."
Navy: "On, above and below the water, the Navy is America's forward-deployed force and is a major deterrent to aggression around the world."
Air Force: "The Air Force provides a rapid, flexible, and lethal air and space capability that can deliver forces anywhere in the world within hours."
Coast Guard: "The Coast Guard provides law and maritime safety enforcement, marine and environmental protection and military naval support. Part of the Department of Homeland Security during peacetime, the Coast Guard operates under the Navy during times of war."
National Guard: “Comprised of the Army National Guard and Air National Guard, the National Guard is a versatile force supporting combat missions domestic emergencies, humanitarian efforts homeland security and more.”