Does cell prio come into picture in cell selection procedure?

Hi Experts,
I have very basic query in cell selection procedure: does cell prio come into picture or not?
I.e. we define number from 7 to 0.

Only in cell reselection.
In cell selection it has no importance priority.

Oh, I see. Today I met some confusion: then what is importance of sib 3 cell prio parameter, that we define for serving cell.
My perception till now is that UE select TDD cell as we define cell prio 7 for it, then for FDD we define 6.

For cell reselection priority is important.
But for cell selection it does not matter.
Reselection happens in less than a second.
You may not even notice it.

Then how UE will decide it needs to select cell from TDD and FDD? Which are colacted?
I agree with you as some other expert inform me same as well.
But still a bit confused.

Cell selection is first eligible cell that UE finds.
Then it reselects according to priorities.

Yes at first moment how UE selects cell is it signal level or some other factor after PLMN scan
Srxlev = rsrp meas - qrxlevmin + pcomp

It selects all the cells eligible and attempt registration on each, one by one.
If on different carriers.

Cell prio parameter in SIB3 play crucial role.
Doesn’t understand why we keep no then high for TDD and low for FDD…

This is just for reselection.
So high for TDD means UE will stay on TDD.

If UE is camping on a higher priority cell, UE only start measurement on lower priority cells if source cell signal quality is not good.
If UE is camping on a lower priority cell, UE will always search for higher priority cells.
Serving and neighbor priority are in sib.