Party
A party is a group of players. Players can form a party to tackle many group activities such as 
Dungeons, 
Trials, 
FATEs, 
Guildhests, 
Treasure Hunts and certain 
quests. Players can use the 
Duty Finder to automatically form parties across the servers for many duties.
A Light Party consist of 4 players while a Full Party consist of 8 players. An alliance consists of 3 full parties or 24 players.
- Additionally players can use the Party Finder, introduced in patch 2.1, to form parties with specific goals by filtering players with certain requirements.
Types of Parties
Light Party
Light Party consist of 4 players, typically 1 
Tank / 1 
Healer / 2 
DPS. Nearly all of the Dungeons, Guildhests, and low level Trials are designed for a light party.
Full Party
Full Party consist of 8 players, typically 2 Tanks / 2 Healers / 4 DPSes. 
Normal Raids along with all the endgame Trials are designed for a full party.
Alliance
Alliances consist of 3 full parties of 24 players. The role mix is different for alliances:[1] three separate Full Parties of 1 Tank / 2 Healers / 5 DPSes. Alliance Raids are the primary content for this.
Tools
Others
Notes
- ↑ As of at least Patch 2.3 and the release of Syrcus Tower. When The Labyrinth of the Ancients was added in Patch 2.1, it used the same Full Party composition as other duties.