According to the basic definition, Nibbana is a state of having no more greed, no more aversion and no more ignorance. That's it, that's the definition. You could also add to that definition, that it's a place where nothing is born and nothing dies. And that part is a little bit confusing. The first part makes sense, you've ended all your greed, you've ended all your aversion, you've ended all your ignorance. That's real, we can understand that. The minute there is this other part about a place where nothing is born and nothing dies, it makes no sense to us, because we have no experiential understanding whatsoever of how there can be a place where nothing is born and nothing dies and yet, according to the scriptures, beings are going there somehow.
So those sorts of words make no sense to me, really; but the first part of it, the main definition, that makes sense. That's a direction to go in. It's not so much that we think of Nibbana as a place to go to; but more of a direction for the mind, a direction to purify, to actually end this greed, aversion, ignorance that we have. To purify inside and then find total peace within ourselves. The state of Nibbana.