Is Nibbana a "Realization"?

I read the following on the internet: > But the core of the **Realization has nothing to do with causality**, > otherwise Nirvana would still be subordinate to Samsara, while in fact > Nirvana is famously unconditioned which is to say it transcends > causality. The first time it [Nirvana] is perceived is referred to as a realization aka awakening to a truth never seen before. What Pali or Sanskrit words in Buddhism are usually used to mean 'Realization'? Is Nirvana a Realization? Is Realization a nama-dhamma (mental phenomena) or can it be an asankhata-dhatu (unconditioned phenomena)? Can Realization be unconditioned & have nothing to do with causality? What Pali or Sanskrit words in Buddhism are usually used to refer to attaining the experience of Nibbana?