Zen is a Japanese school of Mahayana Buddhism that lays emphasis on the value of meditation and insight. It was introduced to Japan from China in the 12th century.
The purpose of Zen is spiritual discipline to reach enlightenment (satori) through meditation in a seated posture (zazen.) A practitioner receives guidance from a teacher, and often uses paradoxical statements, stories, and puzzles (koans) to rise above mere intellectual reasoning and realize insight.
Owing to the consequential emphasis on harmony and mental tranquility, Zen has had a profound cultural influence on Japanese art and architecture. Zen practice has also inspired Japanese literature, the Japanese tea ceremony, and the Noh dance-theater.
If you understand, things are just as they are; if you do not understand, things are just as they are.