Indian (or Hindu) yoga codified from esoteric practices that are many thousands of years old. It developed several branches to accommodate different personality styles. The major types of yoga are:
Bhakti - a devotional approach that opens the heart; best for those who are primarily emotionally-oriented
Jnana - an intellectual approach that leads to wisdom; best for those who are primarily mentally-oriented
Karma - an active, service-oriented approach; best for those who are more extroverted and who find meaning mostly through relationship
Raja - an energy and meditation-based approach; best for those who focus upon the bottom line and getting things done in a practical way
For those who are capable, Raja Yoga employs the most powerful and direct techniques for spiritual advancement. In addition, it provides a clear outline of the stages of progress along the path. These teachings were first systematized in the Yoga Sutras of Patanjali ( written around 300-500 AD ). The eight traditional stages are:
Yama ( social ethics of non-violence, truth, non-stealing, continence, and non-coveting )
Niyama ( personal ethics of purity, contentment, ardor, study, devotion )
Asana ( discipline of the body through posture to provide a sound base for taming the mind )
Pranayama ( discipline of the breath to refine the base developed through asana )
Pratyahara ( beginning mental concentration, holding to a single object for about 10-20 seconds ) This is the start of meditation, in proper. Achievement to this level brings mental control over the sense gates, so that one can withdraw from sense experience. This is useful because it allows one to further purify the mind and heart without the normal distractions of the mind and senses.
Dharana ( intermediate mental concentration, holding to a single object for 2-4 minutes )
Dhyana ( advanced mental concentration, holding to a single object for 30-40 minutes )
Samadhi ( very advanced mental concentration, holding to a single object for 6 hours or more ) The most advanced practitioners can remain in samadhi indefinitely.
The final practice of this meditational path is to connect the samadhi state with ordinary day-to-day consciousness so that a practitioner is in samadhi regardless of whether he or she is meditating in total isolation or performing daily chores in the normal bustle of people, places, and events.
In this way, the accomplished meditator has quite literally passed beyond life's sufferings but yet remains in the world. A spiritual master of this stature experiences every moment as pleasant and peaceful regardless of what may be happening to her or his body and mind. For instance, such a person would be aware of the body's torment when suffering from some terrible disease, such as cancer, but naturally remain in a serene state anyway.