The term DMZ (De-Militarized Zone), is generally used to describe the geographical area separating North Korea from South Korea in the 1950s, after the Korean War. The entire area was liberally hosed down with Agent Orange, a powerful defoliant, (toxic to humans, and allegedly the cause of many diseases in GIs) that stripped the land of vegitation, in an attempt to prevent cross border incursions
In computer networking and
security terms however, it refers to a
host, small
network, or segment that sits in between a
private network and the
public network as a type of
firewall, typically between your Internet router and host. The DMZ host initiates
sessions for users on the private network when they send
requests for connections on the public network to it (in effect acting like a
proxy server). However, the DMZ host is not able to initiate a session back into a machine located inside the private network and only forwards packets that have already been requested. This prevents from outside coming into the private network (unless the attacker can mask the packets so they look like they're coming from a server requested by a current session). The DMZ host can house
information that the private network
operator wishes to be available to the outside world (ie
webpages), although this information is open to attack.