DMZ is a game modus in Call of Duty Modern Warfare 2 where the player can play on maps from Warzone. The operator get some tasks to do, what let him earn some XP points. The objectives can be limited to one map or multiple maps. Where the player should exfil with items and infil with them in another map.
It gives a big sandbox where everything is possible. Play together with others, play alone. Join other teams when you die or ask to team up.
Follow the guide to get more knowledge about the game modus.