Final answer:
A Do Not Resuscitate (DNR) document is used to provide instructions to medical personnel not to revive or resuscitate a patient if their heart stops beating or they stop breathing.
Step-by-step explanation:
The purpose of a Do Not Resuscitate (DNR) document is to provide instructions to medical personnel, such as doctors and nurses, that if a person's heart stops beating or they stop breathing, they should not take steps to revive or resuscitate the patient. A DNR order is a legal document that ensures that a person's wishes regarding life-extending treatment are respected, especially if they are unable to express their desires due to incapacitation. This document is often used in cases where a person is terminally ill or prefers not to be resuscitated in specific circumstances.