A lot of people believe that the term appellation of origin is synonymous with viticultural area , but that's not the case. Viticultural areas are to appellations like grapes are to fruit. Viticultural areas are one kind of appellation. Not all appellations are viticultural areas. An appellation of origin can be the name of a country, the name of a state or states, the name of a county or counties within a state.
Viticultural areas are a hybrid appellation.
In terms of plantings, a viticultural area may be filled with vineyards or could be almost sparse. In terms of quality, there is no guarantee that a wine labeled with a viticultural area is any better or worse than wines that don't bear such information.