PCI stands for "Payment Card Industry." PCI refers to a set of standards that are designed to ensure the secure handling of credit card and debit card transactions by merchants and service providers. The PCI standards are developed and maintained by the Payment Card Industry Security Standards Council (PCI SSC), an organization that was established by the major credit card brands (Visa, Mastercard, American Express, Discover, and JCB).

The PCI standards apply to any organization that processes, stores, or transmits credit card or debit card information. These standards are designed to protect cardholder data and reduce the risk of credit card fraud and other security breaches. Organizations that handle cardholder data are required to implement a set of technical and operational controls to ensure the security of cardholder data, and to undergo regular assessments to ensure compliance with the PCI standards.

There are several different versions of the PCI standards, including the PCI Data Security Standard (PCI DSS) and the PCI Point-to-Point Encryption (PCI P2PE) Standard. The specific requirements that apply to an organization depend on the type of cardholder data that the organization handles and the nature of its business.