Samsara is mind pulled outward when beholding externals.

Lost and confused in the deluded belief in the reality of what the mind itself creates through interpretation, and then projects outward, externals are perceived to be absolute independent self-existing reality.
We are caught.

Nirvana is mind turned inward and recognizing the true nature of externals.

Recognizing the mind’s true nature, perceived externals are recognized as the mind’s projections, and then their seeming reality dawns into understanding.
We are freed.