Yoga is a physical, mental, and spiritual discipline, originating in ancient India, whose goal is the attainment of a state of perfect spiritual insight and tranquility. The word is associated with meditative practices in Hinduism, Buddhism and Jainism. The Sanskrit word yoga has the literal meaning of "yoke", from a root yuj. As a term for a system of abstract meditation or mental abstraction it was introduced by Patanjali in the 2nd century BC. Someone who practices yoga or follows the yoga philosophy with a high level of commitment is called a yogi or yogini.