What is the military? In simple terms, it is made up of the six armed service branches: Air Force, Army, Coast Guard, Marine Corps, Navy, and Space Force. There are three general categories of military people: active duty (full-time soldiers and sailors), reserve & guard forces (usually work a civilian job, but are occassionally called to full-time military duty), and veterans and retirees (past members of the military). 

The President is the Commander in Chief. He/She makes all final decisions, but the real work is done by those below him/her. The Department of Defense (DoD) has control over the military and each branch. With over 2 million civilian and military employees, the DoD is the world's largest "company."

Each branch of the military has a unique mission within the overall mission of U.S. security and peace. Here they are in a nutshell:

Air Force: The Air Force protects American interests at home and abroad with a focus on air power. 

Army: As the oldest branch of the U.S. Military, the Army protects the security of the United States and its resources. 

Coast Guard: The Coast Guard is a maritime force offering military, law enforcement, humanitarian, regulatory and diplomatic capabilities. 

Marine Corps: The Marine Corps is often first on the ground in combat situations. 

Navy: The Navy delivers combat-ready Naval forces while maintaining security in the air and at sea. 

Space Force: The Space Force defends U.S. interests on land, in the air, and from orbit with a range of advanced training and technology.