The United States has eight federal uniformed services that commission officers on a full-time basis as defined by Titles 10, 14, 32, 33, and 42 of the U.S. Code. Six of these services comprise what are generally referred to as "Military" or armed forces. Two of these services are considered non-armed and have a specific domestic focus - though, either of the two unarmed services can be placed under the control of the military by order of the President. And then each state also has its own National Guard branch.
Federal law names the six armed forces as the Army, Marine Corps, Navy, Air Force, Space Force, and the Coast Guard. Now, the Coast Guard is unique for a few reasons. First, during peace time it falls under the purview of the Department of Homeland Security while the other five armed services are all under the authority of the Department of Defense. Second, though it specializes in maritime operations, the Coast Guard is also a federal law enforcement agency.
Finally, more unique than the Coast Guard is something known as the National Guard. These are state-based military forces that are generally under the control of their state's respective governor. However, when activated at the federal level (during times of war or national crisis) they become part of the reserve components of the U.S. Army and the U.S. Air Force. The National Guard services are structured and operate almost the same as other military reserve services. Most of their members hold full-time civilian jobs and only serve in a military capacity around one weekend a month - unless they are activated to respond to a natural disaster or other state emergency.
Army: The largest and oldest service in the U.S. military, the Army provides the ground forces that protect the United States. Click here to learn More.
Marine Corps: A component of the Department of the Navy, the Marine Corps maintains amphibious and ground units for contingency and combat operations. Click here to learn More.
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. Click here to learn More.
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. Click here to learn More.
Space Force: The Space Force organizes, trains, and equips space forces in order to protect U.S. and allied interests in space and to provide space capabilities to the joint force. Click here to learn More.
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. Click here to learn More.
National Guard: Composed 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 operations and more. Click here to learn More.
Public Health Service Commissioned Corps: This is the uniformed service branch of the United States Public Health Service. Their primary mission is the protection, promotion, and advancement of health and safety of the general public. This Corps is headed by the Surgeon General of the United States. Click here to learn More.
The National Oceanic and Atmospheric Administration Commissioned Officer Corps: NOAA is a scientific agency overseen by the Department of Commerce. Their primary mission is to monitor oceanic conditions, support major waterways, and monitor atmospheric conditions. Click here to learn More.
For even more information, check out some of the links below.