The is the type of vine used for wine production. Each variety provides a wine with different characteristics and aromas.
In the Bordeaux winegrowing region, the red and rosé appellations primarily consist of the grape varieties Merlot (65%), Cabernet Sauvignon (23%), Cabernet Franc (10%), and 2% other varieties (Malbec, Petit Verdot).
The white Bordeaux appellations primarily use Semillon (47%), Sauvignon Blanc (45%), Muscadelle (6%) and 2% other varieties (Colombard, Merlot Blanc etc.).
One particular feature of Bordeaux wines is the use of blends, i.e. wines made from a combination of multiple different grape varieties. However, blending is not mandatory: for example, you could taste a Médoc (AOC) made from 100% Merlot.
Source: Bordeaux Wine Certificate, 2015 figures