Nomen vs Res

I'm not sure what you are asking here.

Nomen means "name".
Res means "thing".

In Latin, as in English, you might choose to use the term nomen or "name"
to mean a concept or category or classification and res or "thing" to mean
an instance of that "name" or nomen. However this is nothing specific to
Latin.

This sort of discussion belongs to the realm of philosophy. We have several
members of this forum who could go on for pages about it.

Thanks George.
And yes, the general motivation for the question is certainly philosophical in nature!