What is nirvana?

Nirvana, in no way equating with death, is thorough liberation from rebirth and redeath. It says in The Agamas: ‘Birth and death forever terminated, pure practice complete, whatever needing done be done, and no ensuing existence be received, all is known in accordance with the truth.’

At that, birth and death forever terminated and no ensuing existence be received best define nirvana. Plainly and simply.