Not much difference to me. Intuitively, I envision a hobble as including both legs and limping only one. Also, since hobbling can be an act perpetrated on an animal/person (binding their ankles), it seems somewhat involuntary. Limping, to me, always implies an injury or physical deformity.

hobbling is due to old age like characteristic or by disease/sickness. Limping is due to an injury.

Hobbling and limping are pretty much synonyms for each other. The words are just used in different situations. For example, you could refer to a person as limping. They've likely hurt their leg or both legs in some way. Similarly, you could say an animal such as a dog or horse is limping. Usually, when we use hobble we're referring to someone of old age having trouble walking. For example, you could say the old woman is hobbling to her car.