The following article is about the term Nirvana in the context of Buddhism. See Nirvana (disambiguation) for other meanings.
Nirvana (Sanskrit -- Pali: Nibbana -- "beyond all that can be described or defined") is the "goal" of Buddhism. In Chinese Buddhist scriptures, the word is transliterated as Nie4 Pan2 (涅槃). Siddartha Gautama, the Buddha described Buddhism as a raft which, after floating across a river, will reach nirvana.
As a term, it denotes the extinguishing or "blowing out" of a fire or candle flame and carries the connotations of stilling, cooling, and peace. This state is in opposition of suffering in which all greed, aversion, delusion, ignorance, craving and ego-centered consciousness are extinguished. Often considered ineffable, Nirvana may be denoted as a continuity of void processes.
According to the physics taught at the time of the Buddha, a burning fire seizes or adheres to its fuel; when extinguished, it is unbound
To Brahmin and Indian thought during the time of Gautama Buddha, when a fire was extinguished it went into a state of latency. Rather than ceasing to exist, it became dormant and in that state -- unbound from any particular fuel -- it became diffused throughout the cosmos. When the Buddha used the image to explain nibbana to the Indian Brahmans of his day, he bypassed the question of whether an extinguished fire continues to exist or not, and focused instead on the impossibility of defining a fire that doesn't burn: thus his statement that the person who has gone totally "out" can't be described.
However, when teaching his own disciples, the Buddha used nibbana more as an image of freedom. Apparently, all Indians at the time saw burning fire as agitated, dependent, and trapped, both clinging and being stuck to its fuel as it burned. To ignite a fire, one had to "seize" it. When fire let go of its fuel, it was "freed," released from its agitation, dependence, and entrapment -- calm and unconfined.