Credit card issuers are financial institutions, such as banks or credit unions, that provide credit cards to consumers and businesses. They evaluate applicants' creditworthiness and set credit limits based on factors like income and credit history. Issuers also determine interest rates and fees associated with the cards. These institutions manage the accounts, process transactions, and handle customer service. They earn revenue through interest charges, annual fees, and transaction fees from merchants. Popular credit card issuers include Visa, Mastercard, and American Express, each offering various card options tailored to different spending habits and rewards preferences.