Could you explain what exactly means and what is the purpose of the "Logical Only" option in Er-Win table and column definition?

Logical Only CheckBox
Specifies whether the domain should only appear in the logical model.
Select this check box if you want the selected domain to appear in the logical model
only.
Clear this check box if you want the selected domain in the physical
model.
If you are working with a logical-only model and select this check box,
when you derive a new physical-only model, the selected domain does not
appear in the new model.
Note: When you select or clear the check box in the Navigation Grid, your
selection is automatically reflected in the Logical Only check box in the General
tab.

I don't know if  Iwell expressed me in my doubt.

My dificulty is not on how to operate Erwin.

It's more a conceptual doubt. What is the concept underlying in to create an only logical column and a only logical table.

What is the purpose in doing that ? What situations demands it. If possible with small examples.

Thanks!