The DMZ stands for Demilitarized Zone, which is a strip of land running across the Korean Peninsula near the 38th parallel north. It is a border barrier that divides the peninsula roughly in half and was established to serve as a buffer zone between North Korea and South Korea under the provisions of the Korean Armistice Agreement in 1953. The DMZ is 250 kilometers (160 mi) long and about 4 kilometers (2.5 mi) wide. It is a de facto border barrier that runs in the vicinity of the 38th parallel north, which divides the Korean Peninsula roughly in half. The DMZ is a physical or logical subnet that separates a local area network (LAN) from other untrusted networks. It is a perimeter network that protects and adds an extra layer of security to an organizations internal local-area network from untrusted traffic. The DMZ is a fundamental part of network security, and it creates a layered security structure that lessens the chance of an attack and the severity if one happens.