This document discusses death and different types of death. It defines death as the permanent loss of vital functions and introduces the new concept of brain death. It describes three types of death: somatic, molecular, and brain death. Somatic death is the irreversible stoppage of circulation, respiration, and brain functions. Molecular death is death at the cellular level, which can continue for hours after circulation stops. Brain death can be cortical, brain stem, or whole brain. Brain stem death is the loss of vital centers controlling respiration and consciousness. Criteria for determining brain death include the Philadelphia protocol, Minnesota criteria, and Harvard criteria, which evaluate responsiveness, breathing, movements, reflexes, and EEG results.