What are Sephiroth?

https://gnosticteachings.org/faqs/kabbalah/781-sephiroth.html
The ten Sephiroth of universal vibration emerge from the Ain Soph, which is the Microcosmic Star that guides our interior.  This Star is the Real Being of our Being.
Ten Sephiroth are spoken of, but in reality there are twelve; the Ain Soph is the eleventh, and its tenebrous antithesis is in the Abyss, which is the twelfth Sephirah.
These are twelve spheres or universal regions that interpenetrate each other without confusion. These twelve spheres gravitate in the central atom of the sign of the infinite.  Solar humanity unfolds in these twelve spheres.  We have said that the sign of the infinite is in the center of the earth, in the heart of the earth.  The Sephiroth are atomic.  The ten Sephiroth can be reduced into three tables:

1. A quantum table of the radiant energy that comes from the sun.
2. An atomic weight table of the elements of nature.
3. A molecular weight table of compounds.

This is Jacob’s Ladder which goes from earth to heaven. All of the worlds of cosmic Consciousness are reduced to the three tables.