Through a power of attorney, "the grantor" (or principal) designates an "attorney-in-fact" (or agent) to act on his or her behalf in circumstances which may be either broad or limited in scope. California law allows for various forms of powers of attorney, including durable, general, limited, medical, guardianship, tax and motor vehicle; however, they are most commonly used for financial and medical purposes.
The earliest form of advance directive was proposed in 1969 by Luis Kutner to help a person communicate their healthcare desires should they be unable to speak for themselves. Because it goes into effect while the person is still living, it is frequently referred to as a "living will."
Suppose you were seriously injured in an accident, comatose, or suffering from a debilitating illness. When your ability to communicate is compromised, an advance health care directive speaks for you, ensuring that your wishes are carried out by your loved ones and by the medical professionals who care for you. Through an advance healthcare directive you can appoint someone who has power of attorney to make decisions on your behalf, provide detailed written instructions as to your specific wishes, or both.