Nirvāna, which is the Saanskrit from of the Pāli- Nibbāna, is a combination of 'ni' and 'vāna' means selfish desire. So Nibbāna means the cessation of selfish desire, the absence of craving, hatred and ignorance.
Nibbāna means the highest refuge: safety; unique: absolute purity: Supramundane: security; emancipation: peace: and so on, there are many positive definition. Nibbāna is, therefore, freedom, thought, does not mean freedom from circumstance, nobody is free from circumstances. It is freedom from the bonds with which we have bound ourselve to circumstances, my circu my activities, my, my; so we bind ourselves to our circumstances, make circumstances as our own. This Nabbāna is freedom from those bonds, and every kinds of infelicity. Nibbāna of the Buddhists is neither a mere nothingness nor a state of annihilation.
Nibbāna is an ultimate truth which is uncreated and unformed, hence it is boundless, to be sought after happiness, because it is free from all sufferings, free from birth, death and so on, Nibbāna is not situated in any place nor is it a sort of heaven where a transcendental ego resides, It is getting out of the circle of existence.
Where, however, there is no birth, there can be no passing away, where, there is no existence, no suffering can exist. Now, as with the extinction of all selfish craving all its concurrent phenomena, such as conceit, self-seeking, greed, hate, anger and cruelty, come to extinction, therefore this freedom from selfish craving signifies the highest state of selflessness, wisdom and holiness.
How is NIBBĀNA to be attained?
It is by following The Bible Eightfold path.