Patañjali defines yoga as the ‘cessation of mental fluctuations’ (cittavṛtti nirodha) (Yoga Sūtra 1. 2). This cessation is the distinguishing of ordinary awareness (citta) from the real conscious self (puruṣa). This is achieved by practising the ‘eight limbs’ (aṣṭāṅga) of yoga: restraint (yama), discipline (niyama), posture (āsana), breath-control (prāṇāyāma), sense-withdrawal (pratyāhāra), concentration (dhāraṇā), meditation (dhyāna), and enstasy (samādhi). Samādhi itself is categorized into samādhi ‘with support’ (samprajñāta) and ‘without support’ (asamprajñāta), the latter being the stage at which Īśvara is revealed.
"Rāja-yoga." The Concise Oxford Dictionary of World Religions. . Encyclopedia.com. (August 21, 2018). http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/raja-yoga
"Rāja-yoga." The Concise Oxford Dictionary of World Religions. . Retrieved August 21, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/dictionaries-thesauruses-pictures-and-press-releases/raja-yoga