Let us use an analogy that our Sages did not employ: that of black and white cinematography.
Light is projected through a film onto a screen.
Areas of darkness on the film create the images on the screen.
This means that the world of a movie, in which characters move and converse, live and die, is created by light and shadows.
The light is the backdrop, and the world of the movie appears where the light is hidden, to one degree or another.
Similarly, the world is composed of dancing shadows that have no substance compared to the source of light.
This is an expression of the concept that “everything before Him is literally considered nothingness.”
It is the perspective that “He is alone in the upper and lower worlds, just as He was alone before the six days of Creation.”
The world that appears so tangible to us is not a new, independent existence but only a darkness concealing God’s existence.
It is an illusion.
Rabbi Adin Steinsaltz