Rāja yoga has variously referred to as “royal yoga”, “royal union”, the path of self-discipline and practice. Raja Yoga is also known as Ashtanga Yoga (Eight Steps of Yoga), because it is organised in eight parts: Yama – Self-control. Niyama- Discipline. Asana – Physical exercises.
Raja yoga is a modern retronym introduced by Swami Vivekananda when he equated raja yoga with the Yoga Sutras of Patanjali.
The Yoga Sūtras of Patañjali are a collection of 196 Indian sutras (aphorisms) on the theory and practice of yoga. The Yoga Sutras were compiled prior to 400 CE by Sage Patanjali who synthesized and organized knowledge about yoga from older traditions.The Yoga Sūtras of Patañjali was the most translated ancient Indian text in the medieval era, having been translated into about forty Indian languages and two non-Indian languages: Old Javanese and Arabic