Facets
The world is split up into 5 facets.
Felucca
The facet before there were others, Felucca is the original. This facet allows non-consentual PvP and the stealing from other players. Player housing is allowed in Felucca.
Trammel
Introduced with the Rennisance expansion, Trammel was the first facet in which players were safe from the actions of other players.
Ilshenar
Introduced with Third Dawn, Ilshenar was originally only able to be used with the 3D client. With the Blackthorn's Revenge expansion the 2D client was changed to allow access to Ilshenar.