人生 (rén shēng) refers to a person's entire life or journey through life — the broad, philosophical concept of human existence. It differs from 生活 (shēng huó), which is about daily living and routine, and from 生命 (shēng mìng), which is biological life or the state of being alive. 人生 is more abstract and reflective, often used in discussions about purpose, stages, or meaning.