Zen primarily refers to the training practiced in the Zen sect, which is a sect of Mahayana Buddhism, and its purpose and manners vary depending on the sect. Zen in Buddhism began about 2,500 years ago when Buddha spread grass under a Bodhi tree. It comes from the fact that he sat cross-legged, kept his breath steady, and attained endtghtenment. In Japan, the Rinzai sect was spread by the monk Eisai around the 11th century. It is said that it was spread by the Soto sect, which was also founded by the monk Dogen. In modern times, it is recognized as spiritual training, regardless of redtgion or sect. It is sometimes held as a training experience not only for monks but also for the general pubdtc.