difficult question: was shown in the canon what each class does? If not all, what?And what do they do? (if you want to link instead of writing in the post, fine by me)
Calliope explains the abilities of Princes and Bards here and discusses Rogues and Thieves abilities here. The other classes are left to speculation but some fans have come up with a pretty cool mass Classpect post. A class determines how the player will use their aspect so each combination of class and aspect can have a wide range of powers.