In viticulture differently used term with in the individual countries different meaning. The word comes from the French cuve (Vat or wine container). In the original sense, this means a certain amount of wine in a container (a barrel of wine, so to speak). In German-speaking countries, this usually means artful mixing of wines from different grape varieties. But you can do that too grape musts be fermented together, as on the southern Rhone is common. Other names are blend (New world), Cape Blend (South Africa), CVC (Conjunto de Varias Cosechas in Spain), Coupage. Marriage, Mélange (France for spirits) and Meritage (California).
As a rule, same-colored wines are mixed. The term has no meaning in terms of wine law, therefore "Cuvée" says on the label nothing definite, because it can be quite a wine from one vine, from one Single Location or from one vintage his. For example, also an exclusive special bottling a winery for a catering business. In no case is (as in the German-speaking countries not so rarely suspected) the blending of wines in comparison to unmixed Cry a negative quality difference.