The Italian cheese often grated over pasta, with a hard, granular texture, is Parmesan. More precisely, the celebrated original is Parmigiano-Reggiano, a firm cow’s-milk cheese from Italy’s Emilia-Romagna region.
Parmigiano-Reggiano is made in large wheels and aged for at least 12 months; longer aging produces deeper savory flavor, more brittleness, and crunchy crystals. Its name combines Parma and Reggio Emilia, two of the principal production areas. The cheese is traditionally grated over pasta, risotto, soups, and salads, or shaved and eaten on its own.
A common mix-up is treating “Parmesan” and “Parmigiano-Reggiano” as exactly interchangeable everywhere. In the European Union, Parmigiano-Reggiano is a protected designation with strict geographic and production rules. Outside Europe, “Parmesan” can also describe locally produced hard grating cheeses. Grana Padano is another Italian granular cheese, but it is a distinct product with its own protected name and production area.