Zen in Japan
Seon in Korea
Zen in the USA
Zazen (literally "seated meditation"; Japanese: 座禅; simplified Chinese: 坐禅; traditional Chinese: 坐禪; pinyin: zuò chán; Wade–Giles: tso4-ch'an2, pronounced [tswô ʈʂʰǎn]) is a meditative discipline that is typically the primary practice of the Zen Buddhist tradition. The precise meaning and method of zazen varies from school to school, but in general it can be regarded as a means of insight into the nature of existence. In the Japanese Rinzai school, zazen is usually associated with the study of koans. The Sōtō School of Japan, on the other hand, only rarely incorporates koans into zazen, preferring an approach where the mind has no object at all, known as shikantaza.
Zazen is considered the heart of Japanese Sōtō Zen Buddhist practice. The aim of zazen is just sitting, that is, suspending all judgmental thinking and letting words, ideas, images and thoughts pass by without getting involved in them.