Guna means tie-up or knot or quality.
A cognitive scientific comparison of jagat, jiva and Iswara with Tri gunas, gives us good information.
If jagat is in the awareness, it is tamo guns; jagat is dynamic retrieval information stored within as prapancham, which is in jada or potential form.
If Jiva is in the awareness, the individual would be present with associated ego and other associations and affiliations.
The awareness includes both physical and mental forms and traits.
Then it is called rajo guna.
If Iswara is in awareness it is called sattva guna. Iswara is in the awareness means pleasant experience will be filled in the awareness.
If sattva guna matures and ripens it becomes nirguna. Peace, bliss, silence, contentment will be filled in awareness. Then it is called pure consciousness, unoccupied awareness, content-free contentment.
God is trigunaateeta - beyond three gunas and is nirguna; full of bliss, peace, silence transcending awareness of individual and associated qualities.
Nirguna state is absence of mental tie-up or knot.