Yin Yoga is a passive style of yoga. A slow, gentle form with predominantly seated and lying poses that are held for longer periods, usually 3-5 minutes.
In Yin yoga, we don't do muscle building, but dig deeper.
By staying longer in a pose, we strengthen and relax the connective tissue and joints. More space is created in the body, allowing us to release physical and emotional blockages, allowing QI - life energy - to flow freely through the body.