What Is A Hole (And How Does Our Definition Affect How We Understand Reality)?

Consider the holes in doughnuts. No, not the “doughnut holes” made out of the dough, because they’re clearly not holes. “If we do not take the removed dough to be the hole, then what do we take the hole to be? Are holes material things, where material things are physical (like tables and chairs), or are holes immaterial things, where immaterial things are not physical (like abstract entities)? Or are holes not even things at all?”