IMO, any store that retails off the shelf plants is a retail resale store selling items they probably obtained wholesale from a nursery. A nursery usually does the same sort of retail business, but may also have more esoteric varieties being offered. A nursery also usually has areas of 'not for sale' things which may be propagation areas, a sick bay area for plants that may have a disease or insect problem which they are treating, sometimes an area for seed propagation and areas consisting of plants for a landscaping service they provide which are not for sale to the general public. I think there are specialty nurseries which grow wholesale to supply the retail trade which don't have much variety in that they may concentrate on a minimum number of plants to grow for distribution for the retail market. Not fun to browse in due to the limited variety, but I still consider them nurseries since they actually are actively growing the plants.
It's nurseries that combine retail and growing that also have interests in esoteric and uncommon plants which make them the most interesting and fun to browse - and often the most expensive for a purchase. The wonderful markets that
@Kaktus visits and posts about are probably a combination of retail only and also outlets for nurseries. In the context of a market with many outlets and retail enterprises represented, it's close to the best of both worlds. As well as a huge temptation to overspend a budget
.