Mer-ka-ba is Egyptian means "Light Body Vehicle"
Merkaba in Hebrew means Chariot {of Fire}

Contrary to popular belief the Merkaba is not only the Star Tetrahedron~
It is the Entire Energy Field: consisting of the Sphere of Light, the Sushumna/Prana Tube, The Torus, Chakra Energy Vortexes, and various sacred geometries: including 3 Star Tetrahedrons. One is spinning Clockwise, another is spinning Counterclockwise, and the third is Stationary.
The Toroidal Field contains all of the Energies that flow through the Universe. The Two Spinning Star Tetrahedrons pull energies in through their eight vertices and those energies are pulled in and mixed by the corresponding vertices of the Stationary Star Tetrahedron, from which they are distributed to each of the corresponding Chakras. As the correct energies mix in their corresponding Chakras, the chakra seals open and allow the Universal Energies to Flow up and down the Prana Tube from the top and bottom of the Torus. And this allows for Spiritual Ascenion.

Credit Due for animations used
Oneida Judith - Illuminated Chakras https://youtu.be/QBtvjyuf-bQ
Thrive https://youtu.be/lEV5AFFcZ-s
many more to be added...
i only edited together what was already available from the human collective work