Air force
Infantry: Air assault and Airborne infantry, such as the Royal Air Force Regiment, Royal Australian Air Force Airfield Defense Guards, RNZAF Security Forces, and the US Air Force Security Forces, are used primarily for ground-based defence of air bases and other air force facilities. They also have a number of other specialist roles, including Chemical, Biological, Radiological and Nuclear (CBRN) defense, offensive operations in defense of air force assets, and training other air force personnel in basic ground defence tactics.

Special forces: Air Force Special Forces, such as US Air Force Special Tactics, Brazilian Para-SAR, Indian Garud Commando Force and Pakistani Special Service Wing are used in a variety of roles including combat search and rescue, special reconnaissance, direct action, counterinsurgency, intelligence operations, and serving as joint terminal attack controllers attached to ground and special operations forces.

See also: Aerial warfare
Airborne forces
Air force academy
List of air forces
Military aircraft
Security forces
Space force
Cyber force

Notes: 

References: "AFPC – Air Force Personnel Center", Air Force Personnel Center, Joint Base San Antonio, Texas, 2013, webpage: www.afpc.af.mil.
"United States Air Force", U.S. Air Force, 2009, webpage (large): Airforce.com (Air Force recruiting site).
"United States Air Force", U.S. Air Force, 2013, webpage (large): Official Site of the US Air Force (has subpages about the Air Force).
"United States Air Force Fact Sheet", U.S. Air Force, 2013, webpage (large): US Air Force Fact Sheet.
"United States Air Force Facebook Official External Presence", U.S. Air Force, 2013, webpage (large): Official US Air Force Facebook page.
"United States Air Force blog", U.S. Air Force, 2013, webpage (large): Official US Air Force blog.