Satori is the spiritual goal of Zen Buddhism. (in Chinese: wu.) Satori roughly translates into individual Enlightenment, or a flash of sudden awareness. Satori is as well an intuitive experience.   A brief experience of Enlightenment is sometimes called Kensho. Kensho (literally, "seeing into one's own nature"): Semantically, Kensho and Satori have virtually the same meaning and are often used interchangeably. In describing the Enlightenment of the Buddha and the patriarchs, however, it is customary to use the word Satori rather than Kensho, the term Satori implying a deeper experience. The feeling of Satori is that of infinite space.

-from Three Pillars of Zen by Roshi Philip Kapleau.