Gouda and Gruyere are cheeses named for their towns of origin in the Netherlands and Switzerland respectively. They both have nutty, somewhat fruity flavors but the subtle differences between the two make them suited to particular foods and wines.
Gouda hails from the Dutch town of the same name, just outside of Rotterdam. It is made from cow's milk, and makes up roughly 60 percent of all the cheese produced in Holland. Gruyere is the most famous Swiss cheese (alongside Emmental). It is also made from cow's milk but is unpasteurized. Gruyere has an "Appellation d'Origine Contrôlée" status, meaning that only cheeses made in certain districts may label themselves as being Gruyere.
Gouda has a slightly sweet, mild fruity flavor which becomes more robust the older the cheese is. It is often compared to Edam. Gruyere also tastes slightly fruity, however it has more of a nutty aftertaste and is a bit more salty as it is cured in brine for eight days. Aged Gruyere tastes less creamy and more nutty than young versions.
Gouda is a semi-hard cheese with a yellow wax rind. More mature types of Gouda (matured for more than 18 months) have a black rind to differentiate them. The older the cheese, the harder and flakier it becomes. The cheese itself is a deep yellow color. Gruyere is a semi-hard cheese with a brownish-yellow color and small holes. It has a hard brown rind.
Gouda is often served as part of a cheese platter for dessert, as its sweet taste complements fruit. It is also a table cheese and goes well with red wine, beer and slightly sweet rye bread. Gruyere is often used in cooking rather than served on its own, particularly in pasta, gratins and meat dishes, but its most famous use is in fondue. It pairs well with white, red and rose wines.