VARIETIES OF SAMADHI

"A super-conscious state in which an individual experiences his identity with the ultimate Reality, Brahman," is the general definition of samadhi.  However, there are technical variations of it depending upon whether it is in Vedanta philosophy or in Yoga philosophy.

Savikalpa samadhi in Vedanta philosophy is the first stage of transcendental consciousness and is where the distinction between subject and object persists.  The spiritual aspirant in this state may have a mystic vision, with or without form.

Nirvikalpa samadhi means, literally, "changeless samadhi," and in Vedanta philosophy refers to the transcendental state of consciousness wherein the spiritual aspirant becomes completely absorbed in Brahman, so that all sense of duality is erased.

Savichara samadhi in Yoga philosophy refers to the state in which the mind achieves identity with a subtle object of concentration, mixed with awareness of name, quality, and knowledge.

Nirvichara samadhi is a term in Yoga philosophy referring to the state in which the mind achieves identity with a subtle object of concentration, minus name, quality, and knowledge. 

Nirbija samadhi means, literally, "seedless samadhi," which in Yoga philosophy refers to the state in which all thought-waves are entirely stilled and all sense of duality ceases.