Polyurethane is one type of varnish so if you're going to contrast it you'll have to be more specific (phenolic resin or alkyd resin)

Usually oils would be combined with some other varnish, especially on a floor, because they offer nearly zero abrasion or water resistance. You'd think oil finishes like boiled linseed oil or tung oil would offer some water protection because of the oil but they don't. Better than wax or nothing but much worse than varnishes.

This is a table from a book on my shelf by Bob Flexner on the subject, Understanding Wood Finishes. It's a good reference https://imgur.com/a/TzacsLs