Each of the combat classes in FFXIV offers a variety of differing abilities to allow for solo-play. However, your characters true strength will only be realized or you focus on a specific role to play within the FFXIV combat system. In most RPG's and MMORPG's, roles traditionally fall into three primary categories. These are Damage Sinks, Damage Dealers, and Support.
Support keep everyone alive buff the party as well as debuff the enemy. Damage dealers deal damage. Range, Melee, DOT, Spike, Magic, it doesnt matter. Their goal is to drop the enemy as fast as possible. Damage Sinks are the tanks. They absorb or otherwise mitigate the damage inflicted by the enemy and keep their attention fixated on the tank, allowing the other party members to do their job in relative safety.
FFXIV blurs this classic(cheap ffxiv gil) system. While your role was traditionally well defined by your class, most classes have some way to fill each of these roles a little bit. The true beauty or the Armory system is mixing and matching abilities from differing classes to better fill your role in the party, while still being able to switch to a different set of abilities to play by yourself.
