Final answer:
Type 1A diabetes is idiopathic and often associated with obesity, while Type 1B diabetes is characterized by autoimmune factors.
Step-by-step explanation:
Type 1A diabetes, also known as idiopathic diabetes, is characterized by an unknown cause. On the other hand, Type 1B diabetes, also known as immune-mediated diabetes, is most commonly associated with autoimmune factors. Type 1A diabetes is often associated with obesity, while Type 1B diabetes is not.