Yoga philosophy is one of the six major orthodox schools of Hinduism. Ancient, medieval and most modern literature often refers to Yoga school of Hinduism simply as Yoga. It is closely related to the Samkhya school of Hinduism. Yoga school's systematic studies to better oneself physically, mentally and spiritually has influenced all other schools of Indian philosophies. The Yoga Sutras of Patanjali is a key text of the Yoga school of Hinduism.