Wikipedia
Parmigiano-Reggiano (; ), or Parmesan cheese, is a hard, granular cheese. The name "Parmesan" is often used generically for various simulations of this cheese, although this is prohibited in trading in the European Economic Area under European law.
It is named after the producing areas, which comprise the provinces of Parma, Reggio Emilia, Bologna (only the area to the west of the river Reno), Modena (all in Emilia-Romagna), and Mantua (in Lombardy, but only the area to the south of river Po), Italy. Under Italian law, only cheese produced in these provinces may be labelled "Parmigiano-Reggiano", and European law classifies the name, as well as the translation "Parmesan", as a protected designation of origin. Parmigiano is the Italian adjective for Parma and Reggiano that for Reggio Emilia. Outside the EU, the name "Parmesan" can legally be used for cheeses similar to Parmigiano-Reggiano, with only the full Italian name unambiguously referring to Parmigiano-Reggiano cheese. It has been called the "King of Cheeses".