Caretaker = A person employed to look after a building or animals; janitor, warden, watchman.

• He works as a college caretaker.
• Two lions escaped from their cage and killed their caretaker.

Caregiver = someone who takes care of a person who is young, old, sick or differently abled. Some caregivers are family members. Others are paid.

• When she got sick her husband became her caregiver.
• She has become a caregiver for her mother and father.
• Since I am away on my official duties very often I have employed a caregiver for my ailing mother.