A more thorough explanation:

A primary caretaker is the person who has the most responsibility for taking care of a child on a daily basis. This can be a parent or a non-parent who has taken on the role of caring for the child.

In family law, the primary caretaker is often determined based on the tender-years doctrine or primary-caregiver doctrine. These doctrines consider factors such as who has been the primary caregiver for the child, who has provided the most emotional and physical support, and who has been involved in the child's daily activities.

For example, if a child's mother has been the one primarily responsible for feeding, bathing, and taking care of the child's needs, she would likely be considered the primary caretaker. Similarly, if a grandparent has been the one taking care of a child while the parents are at work, they may be considered the primary caretaker.

Overall, the primary caretaker is the person who has the most significant role in a child's daily life and is responsible for their well-being.