Quote Originally Posted by MistakeNot View Post
Classes - Jobs - doesn't much matter what you call them.
It actually matters in the lore. When you first pop into the game you are guided to one of the cities because you choose an starting class. To give an example, there are no Summoners in Eorzea, their arts are lost and you actually learn how to use them using the same principles of the Arcanist class in the quest involved and the guidance of the soul crystal. The jobs are an advanced version of the classes only a few know or its a lost knowledge (or in case of the Machinist, something new).