Military regions (also called Military districts)  are creations of a countries’ armed forces  which are responsible for a certain area of territory. They are often more responsible for administrative than operational matters, and in countries with conscript forces, often handle parts of the conscription cycle.

Navies have also used a similar model, with organizations such as the United States Naval Districts. A number of navies in South America used naval districts at various points in time.

Demilitarized Zones

A demilitarized zone, DMZ or DZ is an area in which treaties or agreements between nations, military powers or contending groups forbid military installations, activities or personnel. A DMZ often lies along an established frontier or boundary between two or more military powers or alliances. A DMZ may sometimes form a de facto international border—for example, the 38th parallel between North and South Korea. Other examples of demilitarized zones are a 120-mile (190 km) area between Iraq and Kuwait, Antarctica (preserved for scientific exploration and study) and outer space (space more than 100 miles (160 km) from the earth’s surface).

Several demilitarized zones have also unintentionally become wildlife preserves because their land is unsafe for construction or less exposed to human disturbances . Examples include the Korean Demilitarized Zone, the Vietnamese Demilitarized Zone, Antarctica  the Green Line in Cyprus.

Source:Wikipedia

Related Reading(s):

Concept of Region

Historical Regions

Culture Regions