I cannot say what enlightenment is and is not, but some of the finest elaborations on enlightenment deal with it in negative terms. For example, the Buddha said enlightenment was the end of suffering.
That tells us what enlightenment isn’t, but it doesn’t tell us what enlightenment is.
My favorite of such descriptions comes from the Zen master Shunryu Suzuki:
Enlightenment is nothing added.
Because it is nothing added, we can’t really say it is a destination. A destination is something new, something that isn’t where you are now.
Enlightenment isn’t something you have, it isn’t an added component. Much of spirituality and the Buddhist way is about dropping things from your mind rather than adding more intellectual stuff or acquiring new objects for the mind to chew on.
So I would lean toward saying enlightenment is a discovery of what is rather than a destination to somewhere else. But then this begs the question: Whose discovery is it?
The seeker, the individual identity we mistake ourselves to be, does not become enlightened. Ram Dass once adroitly said that enlightenment is the ego’s ultimate disappointment. Why? Because the ego wont be around to enjoy it.
Enlightenment isn’t of the person or the individual but rather it is liberation from the dream-like illusion of being an individual. This is not an experience of the body or mind.
So who realizes enlightenment? Some say that it is enlightenment that realizes itself, the Self realizes the Self, and God who knows God.
Of course talking about this kind of thing too much, which is predominantly what I do here on this blog, tends to obscure the reality of it. This is why, although these questions need be asked and responded to, they are best answered through the firsthand communion of tranquil stillness with serene silence.
Two books I’d recommend, if you’re interested in enlightenment, are I Am That by Nisargadatta Maharaj and Be As You Are by Ramana Maharshi.
Namaste brother! Much love.