ζεν, or Zen, is a school of Buddhism that emphasizes meditation and direct experience over theoretical knowledge. Originating in China as Chan Buddhism, it later spread to Japan and became known as Zen. The practice focuses on mindfulness and the cultivation of a calm, clear mind through meditation techniques, such as zazen, or seated meditation. Central to Zen philosophy is the idea of achieving enlightenment, or satori, through personal insight rather than reliance on scriptures or rituals. Zen encourages practitioners to observe their thoughts and feelings without attachment, fostering a deeper understanding of the self and the nature of reality.