You've heard of Zen. You may have had moments of Zen. But what the bleep is Zen?

The popular idea of Zen is that it's, like, Japanese Dada, with kung fu monks. I regret that the popular idea is a tad romanticized.

The nerdy answer to the question What is Zen? is that Zen is a school of Mahayana Buddhism that emerged in China about 15 centuries ago. In China it is called "Ch'an" Buddhism. Ch'an is the Chinese rendering of the Sanskrit word dhyana, which refers to a mind absorbed in meditation. "Zen" is the Japanese rendering of Ch'an. Zen is called "Thien" in Vietnam and "Seon" in Korea. In any language, the name could be translated "Meditation Buddhism."

Here I want to provide a bare-bones introduction to Zen. Note that what follows is barely a handshake. I will use the word "Zen" for all schools, just to keep it simple.

This article also assumes you know what Buddhism is. If you aren't sure, read the Introduction to Buddhism.

Zen began to emerge as a distinctive school of Mahayana Buddhism when the Indian sage Bodhidharma (ca. 470-543) taught at the Shaolin Monastery of China. (Yes, it's a real place, and yes, there is a historic connection between kung fu and Zen.) To this day Bodhidharma is called the First Patriarch of Zen.

Bodhidharma's teachings tapped into some developments already in progress, such as the confluence of philosophical Taoism with Buddhism. Taoism so profoundly impacted early Zen that some philosophers and texts are claimed by both religions. The early Mahayana philosophies of Madhyamika (ca. 2nd century CE) and Yogacara (ca. 3rd century CE) also played huge roles in the development of Zen.

Under the Sixth Patriarch, Huineng (638-713), Zen shed most of its vestigial Indian trappings, becoming more Chinese and more, well, Zennish. Some consider Huineng, not Bodhidharma, to be the true father of Zen. His personality and influence are felt in Zen to this day.

Huineng's tenure was at the beginning of what is still called the Golden Age of Zen. This Golden Age flourished during the same period as China's Tang Dynasty, 618-907. The masters of this Golden Age still speak to us through koans and stories.

During these years Zen organized itself into five "houses," or five schools. Two of these, called in Japanese the Rinzai and the Soto schools, still exist and remain distinctive from each other.

The rest is here:

Zen in Buddhism Introduction (What Is It?)