Out of Combat
Out of Combat describes a player status and is usually referred as OOC. It happens when a player is idle in opposition to being In Combat.
If a player is OOC all the spells and abilities that check this status will change mode or trigger, like the health and vigor regeneration rates.
Also a player in OOC won't be seen as aggressive by monsters or other PVP players.
Getting out of range of a creature may cause a player to enter in OOC status (by teleporting, entering in a portal, jumping out for a different zone, running out of range, etc.)
Getting out of a PVP or KVK zone can take a player in a PVP combat to OOC status.
There are skills that put the player in OOC status like Feign Death.