Yin Yoga is a form of Yoga founded in 1979 by Paul Grilley, an American Yoga master. He integrated the Yin and Yang interplay of the Eastern philosophy, with the Western school of anatomy to develop a set of unique theories.
Yin Yoga involves holding of postures for 3 to 5 minutes or longer while witnessing the changes going on in the body and the mind. By breathing smoothly and steadily while allowing the body to surrender through deep relaxation, the mind gradually becomes still and peaceful.
If you wish to better understand yourself, be more patient, strengthen your will or be more at peace with your body and mind, then Yin Yoga is your ideal practice.