Zen, or ch’an as it was called originally, is a branch of Mahayana Buddhism that first appeared in China in sixth and seventh centuries. Buddhism had earlier come to China from India, the birthplace of the Buddha and Buddhism. When Mahayana Buddhism was introduced it was influenced by the indigenous Chinese religion Taoism. Most scholars believe, for example, that it was from exposure to Taoism that Zen developed its great caution and reluctance towards using words and concepts as the path to enlightenment. From China Zen moved on mainly to Japan, Korea and Vietnam, although it found some acceptance in other regions, as well.
The word ch’an is a transliteration of the Sanskrit word Dhyana, meaning concentration (i.e. meditation). While some schools of Buddhism emphasize elaborate cosmologies, devotional practices, chanted formulas and arcane images and gestures, Zen offers meditation (zazen) as the best way to discover things directly for oneself.
Another distinctive characteristic of Zen is that the historical Buddha is regarded less reverentially than in most other Buddhist traditions. While Zen practitioners may exhibit a high degree of respect and admiration for the Buddha (especially for his solitary quest for enlightenment without the guidance of anyone before him and for his burning desire to cure the world’s suffering), Zen Buddhists consider the Buddha a human being. Thus a bit of irreverence for the Buddha now and then is considered healthy. One Zen master, when he heard a student speak reverently of the Buddha, washed out the student’s mouth with soap! (It should be noted , however, that Zen is certainly not the only tradition that considers the Buddha to be just an admirable person and not a godlike figure.)