Fontina is one of those cheeses whose name has been co-opted for use by cheesemakers in countries other than its homeland. The real deal, Fontina Val d'Aosta (or Valle d'Aosta), so named because it's made in the Aosta Valley, northwest Italy, is an unpasteurised, washed-rind, full-fat cow's milk cheese that is aged in caves for three months or longer. The stuff made outside Italy is fontina in name only - it's softer and milder, without the intensity of the DOP ( Denominazione di Origine Protetta) cheese.
Fontina, when young, is semi-soft, with a pungent aroma (which is usual with washed-rind cheese) and nutty flavour. It becomes firmer as it ages. Although it's a good addition to the cheese board, fontina melts smoothly, without the fat separating out, so it's often used in cooked dishes, including fonduta - the Italian version of fondue. Fonduta is even better when fine shavings of white truffle are added just before serving.