In just one short phrase, Yoga is an ancient spiritual science. It has been known and preserved for thousands of years in many countries all over the world and in the last few decades. It has become well known and popular in the western world due to an emergence of interest in the mystical eastern paths as well as for its practical relevance for the stresses and illnesses of modern day life.
This overview below may help you to find your path. No form of yoga is better than the other; there are different paths as individuals exist. The common of all forms is the reconnecting, the religion or even yoga with God.