A Power of Attorney (POA) is a legal document granting one person the authority to act for another, while conservatorship involves a court appointing a guardian to manage the affairs of someone incapable of doing so themselves.
and the person who can act for the principal is called the agent, or theattorney-in-fact. You can designate both a medical and a financial power of attorney in the event that you're unable to make those choices yourself.