What types of credit cards are there?

• Visa and MasterCard from various issuers are the two most widely used credit cards in the U.S.
• American Express and Discover are other well-known types.
• Affinity cards earn sponsoring organizations’ donations based on your charges.
• Retail cards give you discounts on purchases at a particular store in exchange for higher interest rates.
• Gasoline credit cards earn users rebates on purchases at a particular gas station in exchange for higher interest rates.

Companies are constantly introducing new types of credit cards. It's a good idea to read through the disclosures (even if they're very long) and make sure you know what you're getting.