Yoga literally means “union”, “connections”, or “oneness” and it is not a religion but a universal concept that brings things scattered together. That maybe people, ideas or simply the exercises that help one to bring him/her together.
Theologically speaking, there are four divisions of Yoga. In Sanskrit, they are called Raja-Yoga, Karma-Yoga, Bhakti-Yoga and Jnana Yoga. And the person who seeks this kind of a union is called a Yogi. The worker is called the Karma-Yogi. One who seeks this union through mysticism is called a Raja-Yogi. One who searches for this union in love is a Bhakti-Yogi. And one who seeks this Yoga through philosophy is called the Jnana-Yogi.