There are nominally two aspects to reality. The silent awareness and the changing relative content. In dualistic life, all that is recognised is the changing aspect of reality. But at some point the mind discovers and identifies itself as the source and ground of silent awareness, and the egoic, dualistic identity is transcended. When this is stable and abiding we call it enlightenment or awakening.
But it’s not the whole story yet. Having identified and established the empty boundless awareness as one’s true nature, the changing aspect of experience is now subtly perceived as ‘other’, as not-Self. But since the ultimate nature of reality is singular, the seeming otherness of relativity must be perceptually and conceptually included as one’s nature also. This perceptual penetration and saturation of all apparent boundaries occurs through the ‘felt sense’ and the action of ever-deepening love and devotion in the Self.
In time all perceived boundaries are dissolved into Unity, and the true realisation is revealed, that of consciousness knowing itself fully as a singular wholeness, the indivisible co-existence of change and changlessness.