What is a army base called?
U.S. Army installations are usually referred to as "posts." Air
Force & Navy installations are referred to as "bases."
Therefore, facilities within an Army post would be referred to as
"Post Exchange", "Post Theater", etc. Facilities within a Naval or
Air Force base would be referred to as "Base Exchange", "Base
Theater", etc. Army posts often have "Fort" in the name, although
other terms, including "Camp" are used ("Camp" is also used by the
Marine Corps).