If your ancestor was a farmer, was he a farm owner, a tenant farmer, or farm laborer? The differences are significant and knowing which helps indicate how mobile your ancestor likely was, what types of records he left behind, etc.
Farming isn’t the only occupation where these distinctions are important? Did your ancestor work in a blacksmith shop, or own his own shop? Again, the difference is important.
Sometimes all we have are vague ideas of what our ancestor did–but sometimes we do have more. Use that information to your advantage.