PCI DSS stands for 'Payment Card Industry Data Security Standard'.
PCI DSS was developed by Visa and MasterCard in response to credit card fraud and identity theft to standardise the security surrounding card payments. The aim of the standard is to improve consumer confidence and to ensure that all merchants who process credit card transactions are meeting the required security standards. The standard is also endorsed by Discover Network, American Express and JCB.
To read more about PCI Compliance and what this means to you, below are various links for reference;