in MTG, the subtype is divided in two sections, one is for race, the other for class. Older cards don't have a class, but newer card do. For example, in classic Kamigawa, Takeno has "human samurai" as his subtype. Human is his race, samurai is his class. In the D&D expansion, Aberrant mind sorcerer has "human shaman" as her subtype. In her case, "shaman" is her class (Wotc didnt want to have to retype older cards with sorcerer in their name so they didnt create a sorcerer type). There are lots of classes: soldier, warrior, berserker, knight, samurai, rogue, ninja, wizard, druid, shaman, warlock, cleric, ranger/scout, and those are from the top of my head