Definition - What does Cepage mean?
Cépage is a French term which generally means the variety of a grapevine (varietal). In broader terms it speaks of a "blend", when talking about wine. It refers to the grapes which were used in the wine. Furthermore, encépagement defined as the varietals and the composition of each in the blended wine.
WineFrog explains Cepage
Many people believe that cépage is a direct translation of a varietal. However, it is also used as a shorter term for encépagement.
On a French wine bottle, this is how they describe a blended wine.
In the case of French wine, certain regions are only permitted to grow certain varietals. The wine made in certain sub-regions have a required minimum percentage of these varietals which must be utilized as the base of their wine. Other required minimum percentages of other varietals can then be blended.
Therefore, if a cépage is listed as the one above as 60-40 and it is a wine from the Left Bank, then one can understand that 60% of the wine is Cabernet Sauvignon, as it is the region's main grape. The remaining is Merlot, their second most important varietal.