Zone Security is a term used to describe how safe a given area of the game world is for players in terms of PvP or PK potential. In Legends of Aria, there exists three states of security: Town (Neutral/Outpost), Guarded, and Wilderness.
List of Towns
A town is as it is named: an established location generated by the game engine, rather than players, where you can find NPC Trainers and various other services such as Banks, Crafting Stations and Stables. When in these areas, there will show "Town" below the mini map. There are currently 6 Towns in Legends of Aria.
In addition to Towns, there are Outposts, which follow slightly different rules from Towns. Currently, there are only two Outposts, but more may be added in the future. When in these areas, there will show "Neutral" beneath the mini map.
Worthy of note is that a small area around every Gate is considered Neutral. Unlawful actions here will result in an insant-kill as described below.
In terms of player protection, Towns and Outposts (Neutral) function almost identically. Unprovoked attack will result in Town Guard aggression or instant-death. Attacking anyone who is not an Aggressor will result in a bolt of lightning hitting the attacking player for 5,000 damage. Towns (listed above) will not tolerate Outcasts within their borders, and any that get too close will draw the ire of the guards. Outposts, on the other hand, have no issue allowing Outcasts in their midst, but will not tolerate violence, even against other Outcasts, unless the attacker is a Victim of an Aggressor. Town Guards will also attack any hostile Animals that roam too close.
Guarded areas encompass all regions of the game, except Barren Lands and Dungeon Deception. Aggression or Unlawfulness of any kind in Guarded areas will spawn a powerful Guardian Order NPC capable of killing most players in 1 attack. Entering a Guarded area will show "Guarded" under the mini map.