PCI stands for Payment Card Industry, but usually means The Payment Card Industry Security Standards Council. It’s made up of organizations like Visa, MasterCard, American Express, and Discover. The Council is how these companies cooperate to agree upon a single, common security standard that merchants are required to meet.

PCI DSS stands for Payment Card Industry Data Security Standard. This is a set of security requirements created by the Payment Card Industry, laying out what merchants need to do to protect customer information. The PCI Council requires that merchants meet this set of security requirements if their business accepts, transmits, or processes customer payment cards such as credit or debit cards.