"Establishing a firm seat for himself in a clean place... having directed his mind to a single object, with his thought and the activity of the senses controlled, he should practice yoga for the purpose of self- realization. Holding the body, head and neck erect, motionless and steady, gazing at the tip of his own nose and not looking in any direction, with quieted mind, banishing fear, established in the brahmacharin vow of celibacy, controlling the mind, with thoughts fixed on infinite, he should sit, concentrated, devoted to Ultimate reality. Thus, continually disciplining himself, the yogi whose mind is subdued goes to nirvana, to supreme peace, to union with infinite." (B.G., Chapter 6, Verses 11-15) Raja yoga, i.e., king of all yoga, It is otherwise known as Ashtanga yoga i.e., yoga with eight limbs.
The eight limbs of Ashtanga yoga are: Yama (self-restraint), Niyama (religious observances), Asana (posture), Pranayama (restraint of breath), Pratyahara (abstraction of senses), Dharana (concentration), Dhyana (meditation) and Samadhi (super-conscious state). Yama is practice of Ahimsa (non-injury), Satya (truthfulness), Asteya (non-stealing), Brahmacharya (celibacy) and Aparigraha (non-covetousness) in thought, word and deed. This is the foundation of yoga. Niyama is observance of the five canons viz., Saucha (internal and external purity), Santosha (contentment), Tapas (austerity). Svadhyaya (study of religious books and repetition of Mantras) and Ishvara- Pranidhana (worship of God and self-surrender). Cultivate Maitri (friendship with equals), Karuna (mercy towards inferiors), Mudita (complaisance towards superiors), Upeksha (indifference towards wicked people). You can eradicate jealousy and hatred and attain peace of mind. Ascend the ladder of yoga patiently through its different rungs and attain the highest summit of the ladder, i.e., Asamprajnata Samadhi, wherein all Samskaras (impressions), which bring about successive births are absolutely fried up.
Practise Raja yoga, control the thoughts, discipline the mind, meditate regularly and attain independence, immortality, freedom and perfection (Swami Shivananda, 1998).
Raja Yoga is, in general, stilling of the mind and body through meditative techniques, geared at realizing one's true nature. Bhakti Yoga is simply love and devotion, epitomized today in such practices as worship of various Hindu deities, etc. Karma Yoga is dedication to one's chosen profession and its perfection to God and all sorts of community service, since they are inherently done without thought of personal gain. Jnana Yoga is a process of learning to discriminate between what is real and what is not, what is eternal and what is not eternal.