Is Yoga a Religion? What is the Difference Between Spirituality and Yoga?

Is yoga a kind of religion? It seems like yoga is often thought of as a religious practice with the various Hindu deities, chants, new age language about the divine powers of the "universe" and devotional hymns. The practice could be construed as a religion and the studio a temple with the rituals, greetings and protection of the space as sacred. How is yoga not a religion and just a form or spirituality and what is the difference between the two?