What is actually Nirvana -- what are some Tripitaka sources? What do you know about the Nirvana?

Most of this community people are from all around the world, and may have different teachers, and level of knowledge may vary.

A brief explanation, with reference to the Tripitaka, is much appreciated.



And, can someone please translate this:



It's from the Abhidhamma Margaya ("Way of Abidhamma") by Ven. Rerukane Chandawimala Thero.
There is, bhikkhus, that base where there is no earth, no water, no
  fire, no air; no base consisting of the infinity of space, no base
  consisting of the infinity of consciousness, no base consisting of
  nothingness, no base consisting of
  neither-perception-nor-non-perception; neither this world nor another
  world nor both; neither sun nor moon. Here, bhikkhus, I say there is
  no coming, no going, no staying, no deceasing, no uprising. Not fixed,
  not movable, it has no support. Just this is the end of suffering.


Ud 8.1

Nibbana is not a conceptually constructed, ideological, 'thing'. It is described as the unconditioned element. As all concepts are conditioned by a mind, it cannot be reached by mental fermentation. It can be approximately described by negation - not impermanent, not unsatisfactory, not self (etc). But even that is still conceptualisation. Better meditate, attain jhana, and find out for yourself.