In layman's term, Zen meditation is letting go of pessimistic thoughts and simply relaxing. In Buddhism, it is a contemplative discipline performed to achieve calmness in the mind and body. Most importantly, it aims for a practitioner to understand the nature of life to obtain enlightenment. To fully experience positive results of Zen meditation, there are three general methods to consider such as Concentration; Koan Introspection; and Shikantaza.
Gurdjieff has prepared a group of dancers. The dancers created such a meditative energy, such a great wave of energy, that those who had come just to see the dance, suddenly forgot the dance completely. Something else was there by the side, a door opened through it.. (commentaries by osho)