Sometimes you wonder if there was a massive game of Chinese whispers or the telephone game going on between French and English. A raisin is a grape, and a bunch of grapes is a grappe de raisins.
Most of the grapes grown in France are wine grapes (surprise, surprise), but there are two AOP table grapes that start to appear in late August: white Chasselas de Moissac and black Muscat du Ventoux.
If you want dried grapes, aka raisins, ask for raisins secs.
If you want sultanas (dried white grapes), look for raisins de smyrne. These are generally in the baking section of the supermarket.
Raisins de Corinthe are currants—the small black raisins that you put in scones, which originally (and still do) come from Greece, made from the Black Corinth grapes grown mainly on the island of Zakynthos (Zante).
Image by rics1299, Creative Commons License