PCI Data Security Standard is a set of requirements for protecting payment card information. It was developed by the PCI Security Standards Council (PCI SSC). The standard is designed to help protect credit card information stored or processed by merchants, as well as their service providers.
The PCI DSS is intended to provide a minimum level of protection for all companies that store, process or transmit cardholder data. It is not intended to be an end-all solution, but rather a framework to build upon. In order for companies to be compliant with the PCI DSS, they must pass an annual audit by a Qualified Security Assessor (QSA).