Nirvana

The understanding of Nirvana I like/understand is the idea that Nirvana means the extinguishing of fire. Mainly the three fires that cause human suffering. These fires are Greed, Hate and Delusion.

IMO this idea is important because these passions/fires are what causes our self destruction.

I know other concepts of what Nirvana is exist, like non-self or a kind of heaven, ultimate bliss...
Personally I don't find these concepts as useful or even particularly appealing.

What is your understanding of Nirvana?

Understanding existence. Quantum Mechanics and all.

I understand nirvana as the preliminary to nirvakalp samadhi. In other words, nirvana is the experience of Nothingness before experiencing Oneness.

Blowing out the fires of addiction. It's a state of mind you get to via negation.

Statelessness... like awareness of the freedom of flow