Yoga comes from the root word Yuj meaning to unite or union. It means to unite the Jivātma with the Paramātma – in other words the individual consciousness with the supreme consciousness.
The union of the individual consciousness with the supreme consciousness could be achieved through various paths as suited to the practitioner or Sadhaka. The different paths of Yoga are Jnāna (the path of knowledge), Bhakti (the path of worship), Karma (the path of work), Laya (the path of music), Raja (the path of mind) and Haṭha Yoga (the path of will power). The paths to approach Yoga could be different according to the individual, but Yoga is one, just like India which is one with so much diversity.
There are many definitions of Yoga. Patanjali defines Yoga as Yogaścitta vritti nirodhaḥ (Patanjali Yoga Sūtrās 1.2) meaning Yoga is to remove the disturbances that occur in the mind. The Haṭha Yoga Pradipikadefines Yoga as Prāṇa vritti nirodha meaning Yoga is to still the fluctuations of the breath. Through controlling the breath, one can gain control over the consciousness and by controlling the consciousness, one can have the control over the breath. Thus, there is no difference between the Haṭha Yoga and the Raja Yoga, Yoga is one.
The Raja Yoga is also called as the Aṣtānga Yoga and Patanjali Yoga. The Aṣtānga Yoga is written by the great sage Patanjali in the form of 196 aphorisms or sūtrās and is one of the Śat Darṣanas. It is called so because it involves 8 limbs or steps to attain the union with the supreme consciousness. Thus, by following these steps one can unite the body, mind, and intellect with the soul.
Patanjali was amongst the greatest sages of all time. He was believed to be the incarnation of Ᾱdiśeṣa. There is a conflict of interest in regarding the time of Patanjali. He is believed to have lived in 5th and 2nd century BC and some believe he was Govindapada who was the guru of Śankaracārya. Patanjali was well versed in many fields. He chose to write the commentary for Pānini’s Vyākarṇa Śāstra (Grammar), Caraka’s Śarira Śāstra (Ᾱyurveda). He then wrote Yoga Śāstra for which he became very popular among scholars. His last work focuses on human’s physical, mental and spiritual evolution. Patanjali’s works collectively deals with the development of speech, human body and mind. This is the reason, one salutes Patanjali before studying the sūtrās written by him with the following prayer Manovākhya doṣnam hantre adhipathiye namaḥa.
The eight limbs of Aṣtānga Yoga are Yama, Niyama, Ᾱsana, Prāṇāyāma, Pratyahāra, Dhāraṇa, Dhyāna and Samādhi. These eight limbs are further classified into three groups for better understanding. The Yamas and Niyama are socio-ethical norms to be followed by the individual which disciplines the individual and puts them into the right path towards Yoga. The Ᾱsana, Prāṇāyāma and Pratyahāra makes the individual gain control over the consciousness through body, breath and the sense organs. The Dhāraṇa, Dhyāna and Samādhi put the individual in the spiritual path. Patanjali defines them as the Samyama meaning the last three limbs are merged together and the difference between are very minute.
The Yamas and Niyamas discipline the individual control the emotions and makes the individual to bring a balance in the emotions and passions. Ᾱsana helps the individual to be healthy and strong. These three steps together form the Bahiranga Yoga. Prāṇāyāma and Pratyahāra help the individual to control the mind by regulating the breath and to restraining the sense organs from their objects of desire respectively. These two steps together form the Antaranga Yoga. The Dhāraṇa, Dhyāna and Samādhi takes the individual to the inner self which is the Antaratma and in this stage the individual is in complete harmony with the supreme consciousness. These stages are called as the Antarātma Sādhana. At this stage, the individual realises one true nature and realises the supreme consciousness.
Yoga liberates the mind from the bondage of the body and unites with the soul. Once the mind reaches the soul, one is at peace; this is achieved through the eight steps.