A Living Will is a legal document that outlines a person's preferences for medical treatment in case they become unable to communicate their wishes. It typically specifies the types of life-sustaining measures a person does or does not want, such as resuscitation or mechanical ventilation, in situations where they are terminally ill or in a persistent vegetative state. This document is part of advance care planning and helps ensure that a person's healthcare choices are respected. It is often used alongside other documents like a Durable Power of Attorney for Health Care, which designates someone to make medical decisions on their behalf.