Courtesy of Wikipedia (try spending some time there!!)
Claret is a name used in English for red wine from the Bordeaux region of France, along the valleys of the rivers Gironde, Garonne and Dordogne, including Medoc, Graves and St Emilion. Claret wines are sometimes divided into Left and Right bank Clarets- Left bank clarets include the Medoc, Graves and Pessac-Léognan, whilst Right bank clarets include the St Emilion and the Pomerol. There are also numerous lesser appellations which are sometimes referred to as Clarets, such as Fronsac.
Cabernet Sauvignon is a variety of red grape mainly used for wine production, and is, along with Chardonnay, one of the most widely-planted of the world's grape varieties.
The principal grape in many Bordeaux wines, Cabernet Sauvignon is grown in most of the world's wine regions, although it requires a long growing season to ripen properly and gives low yields. Many of the red wines regarded as among the world's greatest, such as Red Bordeaux, are predominantly made from Cabernet Sauvignon grapes. World-class examples can improve for decades and remain drinkable for a century.
The particularly thick skin of the Cabernet Sauvignon grape results in wines that can be high in tannin which provides both structure and ageability. This varietal, while frequently aromatic and with an attractive finish, also tends to lack mid-palate richness and so is often blended with lower tannin, but "fleshy" tasting grapes, particularly Merlot and, especially in Australia, Shiraz / Syrah. Cabernet Franc is often used in blends with Cabernet Sauvignon to add aromatics. As a group, Cabernet Sauvignon wines are generally full-flavored, with a stronger flavor than Merlot for instance, and with a smooth and lingering "finish".
Cabernet Sauvignon, like all noble wine grape varieties, is of the species Vitis vinifera, and genetic studies in 1997 indicated it is the result of a cross between Cabernet Franc and Sauvignon Blanc.
In 1961, a cross of Cabernet Sauvignon and Grenache produced the French wine grape Marselan.
As you can see, they are related!! :thup