PCI DSS stands for Payment Card Industry Data Security Standard. It is a set of security standards established by major credit card companies to ensure the protection of cardholder data during payment transactions. PCI DSS compliance is mandatory for any organization that handles, processes, or stores credit card information. It includes requirements for network security, data encryption, access controls, regular monitoring, and vulnerability management. Adhering to PCI DSS helps businesses maintain the trust of their customers and reduces the risk of data breaches and financial fraud.