Zone

A Zone is an area of the game. For technical reasons the world of Tyria is divided into zones connected by portals. A portal will always have a sign next to it indicating what zone it leads to. A portal can be recognized by the sign or by the thin translucent white barrier that marks the beginning of the adjacent zone.

There are various types of zones:
 * Cities
 * Outposts
 * Explorable areas
 * Missions
 * Arenas

Missions, arenas, and explorable areas are instanced zones, whereas cities and outposts have districts.

To Zone
"To zone" (as a verb - as in "Everybody ready to zone in?") means to travel through a area boundary into a zone.