The word Zen comes from the Chinese word ch’an-na, which in turn comes from the Sanskrit word dhyana. Dhyana refers to collectiveness of mind or meditative absorption in which all dualistic distinctions like I/you, subject/object, true/false are eliminated. Zen is a school of Mahayana Buddhism that developed in China in the 6th and 7th centuries from the meeting of Dhyana Buddhism (which was brought to China by Bodhidharma) and Taoism.
In this sense, Zen was a religion and its teachings and practices were directed towards self-realisation (kensho, satori) and lead finally to complete awakening (enlightenment). Zen teaches the practice of zazen, sitting in meditative absorption as the shortest, but also steepest way to awakeneing.
Zen stresses the prime importance of reaching enlightenment through the means of zazen and raising awareness. It sees as useless the acts of ritual religious practices and intellectual analysis of doctrines for the attainment of liberation.
I am sharing this information as Zen is a very popular spiritual practice which can be used alongside any religion or belief system. If you click on the ‘Zen’ tab at the bottom of the screen you will see many other posts related to Zen.