Rubbing alcohol is a generic term and is usually manufactured with isopropyl alcohol.
Different brands of denatured alcohol contain various denaturants such as bittering agents. The purpose is to discourage recreational human consumption by including additives that are bad tasting, bad-smelling or nauseating.
A 50/50 mix of either rubbing alcohol and denatured alcohol will work for prep cleaning. Both have good solvents that will remove dirt and grime.