사 (Death) is the end of life, marking the cessation of biological functions that sustain an organism. It is a natural part of the life cycle and can occur due to various reasons, including old age, illness, or accidents. Different cultures have unique beliefs and rituals surrounding death, often reflecting their views on life and the afterlife. In many societies, death is accompanied by mourning practices, which help the living cope with loss. The concept of afterlife varies widely, with some believing in reincarnation, while others hold beliefs in heaven or spiritual realms. Understanding death can lead to deeper reflections on the meaning of life.