A more thorough explanation:

Term: in potestate parentis
Definition: In the power of a parent. This term comes from Latin and refers to the legal authority a parent has over their child. In the past, parents had complete control over their children's lives, including their education, marriage, and even life and death. Today, this term is used in legal contexts to describe situations where a parent has legal authority over their child.
Examples: A child who is under 18 years old is usually considered to be in potestate parentis. This means that their parents have the legal authority to make decisions for them, such as where they live, what school they attend, and what medical treatment they receive. For example, if a child needs surgery, their parents must give permission for the procedure to be done. Another example is if a child is arrested for a crime, their parents may be held responsible for their actions because they have legal authority over them. These examples illustrate how in potestate parentis refers to the legal power a parent has over their child.