B NIRVANA

The understanding of Nirvana is slightly different when it comes to the Theravada and Mahayana schools. Very simply speaking, the term Nirvana means an extinguishing of sorrows/suffering. So achieving the state of liberation or enlightenment can both be termed as Nirvana.

However there are two levels of achievement that one goes through before achieving liberation. Firstly you extinguish afflictive obscurations and that is followed by the extinguishing of cognitive obscurations.

At the first level when you have eliminated afflictive obscurations, you are still left with what are known as the tainted aggregates (the body). This is the state that the Arahat achieves when s/he is alive. This is also called Sopadhishesha Nirvana or Nirvana with residue or Kalesha Parinirvana.

When the Arahat passes away, s/he gives up the tainted aggregates and achieves Nirvana without residue or Nirupadishesha Nirvana or Skandha Parinirvana.

Finally there is the state of the Buddha which is called Non Abiding Nirvana or Apratishtita Nirvana.

The concept of a MahaPariNirvana is a concept of a fully enlightened Buddha passing away.

What I have explained is from a Mahayana perspective. You will find some differences in how this is explained by the various schools. But the differences are subtle. The differences are found in what the two schools believe happen after Nirvana. Essentially they all refer to the final state that is achieved at the end of the Buddhist path.