It is the eighth and final limb of the Yoga Sutra of Patanjali, and comprises the pinnacle of achievements in Samyama, the three-tiered practice of meditation including also dharana and dhyana. Samadhi is Sanskrit word,Its etymology comes from sam (together or integrated), a (towards), and dha (to get, to hold). Thus the result might be seen to be to acquire integration or wholeness, or truth
Sage patangali is divided Samadhi into Samprajnata and Asamprajnat , again Samprajnata is divided further into
First step towards Samadhi is dharna(concentration),then dhyana ( Samadhi).This is the ultimate goal of the Eight Limbs of Yoga.Samadhi is a Hindu and Buddhist term that describes a non-dualistic state of consciousness in which the consciousness of the experiencing subject becomes one with the experienced object, and in which the mind becomes still (one-pointed or concentrated) though the person remains conscious.
In practice Samadhi is said to be the state of being aware of one's Existence without thinking, in a state of undifferentiated "Beingness." Three intensities (depths) of Samadhi are usually understood in Hinduism.
1) Laja Samadhi
3)Nirvikalpa Samadhi (or Sahaja Samadhi)
Laja Samadhi is a latent ("laja"), potential level of samadhi. It begins in deep meditation or trance-even with movement, such as dancing. This kind of samadhi is a state of joy, deep and general well-being, and peaceful meditation.
Savikalpa Samadhi refers to the initial temporary state of full-valued samadhi. The conscious mind is still active, as is the kalpa, meaning imagination. One should compare this meaning to that of sankalpa, which is "wish." Kalpa takes on a different, but related, meaning to sankalpa because one must use imagination or consciousness (kalpa) to envision a wish or desire (sankalpa). Conversely, vikalpa means "against imagination." At this final level of samadhi, the mind has become quiet and given up its desires and attendant. Vikalpa leads to the Truth, releasing one from any binds of mind (which are mostly imaginations). In Savikalpa Samadhi, we get the taste of Bliss and Beingness, but are still attached to our erroneous identification with the body as well as to our numerous worldly attractions.
Nirvikalpa Samadhi is the end result. There are no more kalpas (imaginings, wishes or other products from work of the mind), because the mind is finally under control. Upon entering Nirvikalpa Samadhi, the differences we saw before have faded and we can see everything as one. In this condition nothing but pure Awareness remains and nothing is missing to take away from Wholeness and Perfection. Entering samadhi in the beginning takes effort and holding on to a state of samadhi takes even more effort. The beginning stages of samadhi (Laja and Savikalpa Samadhi) are only temporary. By "effort" it is not meant that the mind has to work more. Instead, it means work to control the mind and release the self. Note that normal levels of meditation (mostly the lower levels) can be held automatically, as in "being in the state of meditation" rather than overtly "meditating." The ability to obtain positive results from meditation is much more difficult than simply meditating. It is recommended to find a qualified spiritual master (guru or yogi) who can teach a meditator about the workings of the mind.
Mahasamadhi (literally great samadhi) is the Hindi term for a realized yogi's conscious departure from the physical body at death. Which is also known as Nirvana.
Mahasamadhi is the final conscious exit from the physical body. Every infinitesimal piece of attachment or karma is completely surrendered unto God and dissolved into the Divine Ocean of Love. The individual transcends to worlds beyond karma and returns to God, merging into transcendental Bliss.Samadhi is the only stable unchanging reality; all else is ever-changing and does not bring everlasting peace or happiness.
Entering samadhi in the beginning takes effort and holding on to a state of samadhi takes even more effort. The beginning stages of samadhi (Laja and Savikalpa Samadhi) are only temporary. By "effort" it is not meant that the mind has to work more. Instead, it means work to control the mind and release the self. Note that normal levels of meditation (mostly the lower levels) can be held automatically, as in "being in the state of meditation" rather than overtly "meditating." The ability to obtain positive results from meditation is much more difficult than simply meditating. It is recommended to find a qualified spiritual master (guru or yogi) who can teach a meditator about the workings of the mind.In the state of samadhi the body and senses are at rest, as if asleep, yet the faculty of mind and reason are alert, as if awake; one goes beyond consciousness. During samadhi, we realize what it is to be an identity without differences, and how a liberated soul can enjoy pure awareness of this pure identity. The conscious mind drops back into that unconscious oblivion from which it first emerged.
In state of Samadhi, the mind does not distinguish between self and non-self, or between the object contemplated and the process of contemplation. The mind and the intellect have stopped and there is only the experience of consciousness, truth and unutterable joy. You may notice the person to be in samadhi for three days, but for him the feeling is so overpowering that it would always be a few moments - it tends to pass off just like that. Sometimes even lifetimes can pass off in this fashion. It is also said that there have been yogis who lived up to 400-500 years and that some of them were still alive. It's hard to believe but this is true.These eight steps of yoga indicate a logical pathway that leads to the attainment of physical, ethical, emotional, and psycho-spiritual health. The achievement of samadhi is a difficult task. For this reason the Yoga Sutra suggests the practice of asanas and pranayama as preparation for dharana, because these influence mental activities and create space in the crowded schedule of the mind. Once dharana has occurred, dhyana and samadhi can follow.
Samadhi is the state of trance in which the object of the mind and the mind become one.