Final Fantasy XIV: A Realm Reborn has classes and jobs. Here’s the connection between the two as explained by Square Enix:
“By achieving sufficient mastery in a certain class, adventurers will be able to begin undertaking the mantle of a related job. For instance, gladiators may rise up as paladins, stout swordsmen who shield comrades from harm; thaumaturges may aspire to become black mages, masters of offensive magic; while conjurers may find a new calling as white mages, masters of healing.”
Today, Square released screenshots for a number of classes and jobs in the game. You can take a look at these below and visit the links above to read about each class and job.
(Note: An Arcanist class exists as well, but Square haven’t shared screens of it.)