Yoga (of Sanskrit Yoga) refers to a physical and mental traditional discipline that originated in India. The word is associated with practices of mediation in Hinduism, Buddhism and Jainism.
According to its practitioners, yoga results in the union of the individual soul with the divine (Brahman, Shiva, Kali, etc.) for those that have a religious stance.
Also, the perception that the self is spiritual and not material, for those who have a spiritual stance, and physical and mental well-being (are the results) for those that have a Rational stance (atheist or agnostic).