Just a name, means whatever the owner of the property wants it to mean. For people who call RVing camping, everything is a campground.
For me, a campground is a place where they let me camp, i.e. roll out a sleeping bag on the ground or on my cot, or put up my tent, and build a fire. If they don't let me do that, it might be a RV park or RV resort, but it is not a campground, even if the owners choose to call it a campground.
Properties can be both RV park/resort and campground, KOAs are typical of destinations that allow both activities, and provide additional facilities like cabins.
I think RV resort is a pretentious name for a RV park, and if they allow camping, it is also a campground.
There are properties that have no RV hookups, but let RVs come in, and those are almost always called campgrounds.
There are some RVers who seek out RV resorts that allow no camping, so that they are not bothered by other peoples' camping activities. My experience is that many of the places calling themselves 'resort' are not the kind of resort these folks are seeking. So if that's what you want, you need to look into the situation, not rely on the name.