In each of the illustrations, at the bottom on the right is the PDO trademark (Protected Denomination of Origin, DOP in Italian).
Gorgonzola is a veined Italian blue cheese, made from unskimmed cow's and/or goat's milk. It can be buttery or firm, crumbly and quite salty, with a 'bite' from its blue veining.
Parmigiano-Reggiano is a hard granular cheese, cooked but not pressed, named after the producing areas near Parma, Reggio Emilia, Modena, Bologna, and Mantova, Italy. Under Italian law only cheese produced in these provinces may be labeled "Parmigiano-Reggiano", while European law classifies the name as a protected designation of origin.
Buffalo mozzarella (Italian: mozzarella di bufala) is a mozzarella made from the milk of the domestic water buffalo rather than from cow milk.
Ragusano is a cheese from whole cows' milk, with medium to long ageing, having a block shape and a square cross-section, with rounded corners. It is possible to find slight grooves on the surface from the cords used to hang the cheese during the ageing process. The external color is a straw to golden yellow, tending towards brown with further ageing.