A villager's Job is set by which Main Hand Item they have equipped. Example jobs include:
Miner
Woodcutter
Quarrier
Farmer
Animal Trapper
Fisher
Crafter
Different races might have different jobs available. For example, I don't think elves would likely cut down many trees, so likely their buildings are crafted from different materials. Their wooden tools are grown directly from appropriate soil by a specialized craftman (Craftelf?)