In Eorzea, adventurers are quite versatile. Once a class is unlocked by speaking to a Guildmaster, you can simply change the weapon in your hand to switch which class you are actively playing as. This task may take some time to build up to - generally speaking, unlocking other classes can be achieved around level 10 or so if you follow the main storyline. Crafting and gathering classes are treated the same way as adventuring classes; switching from Archer to Carpenter will see you running around the world as a Carpenter.
Once you unlock a second battle class, you will gain an Armory Bonus. This bonus applies to experience from fighting monsters and participating in FATEs. It grows larger the greater the discrepancy between your current battle class level and the level of your highest battle class. This eases the burden of leveling multiple battle classes.
|Final Fantasy XIV Classes|
|Disciples of Magic||Arcanist | Conjurer | Thaumaturge|
|Disciples of War||Archer | Gladiator | Lancer | Marauder | Pugilist|
|Disciples of the Hand||Alchemist | Armorer | Blacksmith | Carpenter | Culinarian | Goldsmith | Leatherworker | Weaver|
|Disciples of the Land||Botanist | Fisher | Miner|
|Jobs||Bard | Black Mage | Dragoon | Monk | Paladin | Scholar | Summoner | Warrior | White Mage|