Well, you can call it many things, and it has been. It doesn’t really matter what you call it.

Self-realization is one. Non-duality. Awakening. Realization of Atman, in Hinduism.

There are no endless levels of enlightenment, it’s just what ego likes to think. Enlightenment is the cessation of dreaming. The realization that “all is self” is not true, in the strictest sense, it’s awakening into your dream, the acknowledgment of dreaming. It’s how it feels when you realize that you, kinda, made it all up. There’s still confusion at this stage between what is real and what is not real (self-created), because the mind is still dreaming. But if this was an authentic rather than an intellectual realization, the dreaming will begin to slowly dissolve into the ocean of consciousness. Enlightenment is when this process is complete, and the mind doesn’t dream anymore. Then mountains are mountains again, and other people are also not you. Otherwise, why help them? That would be trying to help yourself hehe.