In general, a variety would be something that's stable and reproducible with the same properties and sufficiently distinct from others. In sexual reproduction y

In general, a variety would be something that's stable and reproducible with the same properties and sufficiently distinct from others. In sexual reproduction you'd expect the variety to be stable if and only if you breed it within itself, and any cross-breeding to result in something that's new. Apple trees are generally pollinated by a large number of other apple seedlings, so it may make sense to consider every individual plant grown from seed as a potential separate variety, so we generally don't do that as the vast majority of these random cross-breeds are bad. Only experimental breeders would even consider apples from individual grown-from-seed plants, everyone else uses genetically identical clones grafted onto rootstock that's (AFAIK) also cloned.