Some card brands, like Visa and Mastercard, are part of a card network or association. These card brands rely on other members of their network to fulfill necessary responsibilities. Networks include issuing banks that issue the card brand’s cards to cardholders and acquiring banks that process payments on their merchants’ behalf.
Card brands Discover and American Express work with acquirers to process transactions, but they do not contract with banks to issue their branded cards. Discover and American Express issue cards to cardholders directly.