The PSN (PlayStation Network) card is essentially a gift card for the PSN digital store run by Sony. This is not to be confused with the PS Plus membership card which is for a membership with PlayStation's premium online service. When items like these cards, which are just a code, are offered as "digital", it usually means they'll just send you the code via email or your Best Buy digital library. Otherwise a physical card with the code will be shipped to you, which is the same card you would find in a Best Buy brick and mortar store.