The Korean Demilitarized Zone is a highly militarized strip of land running across the Korean Peninsula.
Warning shots escalate tensions at Korean DMZ by CNN
It is established by the provisions of the Armistice Agreement for the Restoration of the South Korean State to serve as a buffer zone between the Democratic People's Republic of Korea and the Republic of Korea.
A buffer zone is generally a zonal area that lies between two or more other areas, but depending on the type of buffer zone, the reason for it may be to segregate regions or to conjoin them.
South Korea, officially the Republic of Korea, is a sovereign state in East Asia, constituting the southern part of the Korean Peninsula.
A look inside the DMZ by CNN
The DMZ is a de facto border barrier that divides the Korean Peninsula roughly in half.
De facto is a Latin expression that means "in fact, in reality, in actual existence, force, or possession, as a matter of fact".
A border barrier is a separation barrier that runs along an international border.
Within the DMZ is a meeting-point between the two nations in the small Joint Security Area near the western end of the zone, where negotiations take place.
The Joint Security Area is the only portion of the Korean Demilitarized Zone where North and South Korean forces stand face-to-face.
There have been various incidents in and around the DMZ, with military and civilian casualties on both sides.
Several tunnels are claimed to have been built as an invasion route for the North Koreans.
An invasion is a military offensive in which large parts of combatants of one geopolitical entity aggressively enter territory controlled by another such entity, generally with the objective of either conquering, liberating or re-establishing control or authority over a territory, forcing the partition of a country, altering the established government or gaining concessions from said government, or a combination thereof.