Military branch (also service branch or armed service) is according to common standard the subdivision of the national armed forces of a sovereign nation or state. In classical NATO terminology, the three basic military branches are the Army, Air Force, and Navy.
Countries which do not have access to any of the high seas or any oceans generally do not have a national navy.
In some countries there might be other military branches. In addition to the above-mentioned military branches, examples are:
- In France the National Gendarmerie
- In Germany the Joint Medical Service and the Joint Support Service
- In Italy the Carabinieri
- In Norway the Home Guard and the Cyber Force
- In Poland the Special Forces
- In Russia the Aerospace Defence Forces, Airborne Troops and the Strategic Missile Troops
- In South Korea the Marine Corps (Haebyeongdae)
- In the United States the Marine Corps, the Coast Guard, the Public Health Service and the National Oceanic and Atmospheric Administration
- Emblems of some countries
The military branches came into being in line with military technical progress and have been developed permanently. With that background, the air force was established early in the 20th century as one of the latest armed service.
The army is traditionally the oldest – and in many countries the biggest armed service.