French wine needs no introduction producing quantities between 50 and 60 million hectolitres per year, or 7–8 billion bottles. France is one of the largest wine producers in the world. French wine traces its history to the 6th century BC, with many of France's regions dating their wine-making history to Roman times. Two concepts central to the better French wines are the notion of terroir, which links the style of the wines to the locations where the grapes are grown and the wine is made, and the Appellation d'Origine Protégée (AOP) system. Appellation rules closely define which grape varieties and winemaking practices are approved for classification in each of France's several hundred geographically defined appellations, which can cover regions, villages or vineyards.