Romano and Parmesan cheeses are both hard, dry cheeses, typically grated or shaved and served over pasta, salads and vegetables or used to flavor and thicken sauces. Both Romano and Parmesan cheeses originated in Italy, but also now are made in the U.S. and elsewhere.
Romano cheese first was produced in the countryside outside of Rome. Parmesan cheese originated in the Italian region of Parma.
Romano cheese is a hard, grainy cheese, traditionally made from whole sheep's milk. Parmesan cheese is a hard, granular cheese made from skim cow's milk.
Although similar in appearance, the flavor of authentic Romano cheese is usually sharper than Parmesan because it is made from sheep's or goat's milk, which has a much tangier and more distinct flavor than cow's milk.
The classic Romano cheese, peccorino Romano, is made from sheep's milk; extra-sharp caprino Romano is made from goat's milk cheese; and milder-tasting vacchino Romano is made from cow's milk. The original Parmigiano-Reggiano has the most consistent flavor of all Parmesan-type cheeses.
In the U.S., grated Romano cheese often is blended with grated Parmesan cheese to produce a relatively mild cheese that is more acceptable to those who prefer the flavor of cow's milk products.