The credit card issuer also referred to as the “issuing bank” or “credit card company” is the bank that backs the credit card financially.
The Credit Card Issuer/issuing bank is in charge of:
Credit card processor and Credit card issuers serve entirely different purposes. But, there is no rule that prevents a company from both processing and issuing credit cards.
Example: American Express is both credit card processor/networks and credit card issuer.