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Borderlands makes extensive use of instanced gameplay. An "Instance" is an area within a game that is generated for each group playing. By placing the game content into the confines of a number of instances, a game can restrict the number of rendered objects that the player's hardware has to keep track of within the game environment and therefore maximise system performance. In multiplayer games instances also aid server processing and network demands.
For a more comprehensive description of an instance see Instance dungeon.
"Zone" is a community designated term to describe an instance. A Borderlands zone has a place name and a map. The map defines the confines of the zone and has at least one connection point to another zone. The smallest zones are the Arena staging areas where player versus player matches are set up. The largest zones typically have several connection points to other, smaller zones, and often serve as hubs for major events within the main body of Borderlands.
The largest of the zones are often referred to as "Regions". A region is typically also a vague description covering both a large zone and several satellite zones within the same general area.
A "Location" is a small place within a zone that has a place name. Place names can be found either when a New-U Station is approached for the first time and announces the location by a line of text, or alternatively they can be mentioned in mission briefings.