This document provides an introduction to PCI-DSS (Payment Card Industry Data Security Standard). It defines key terms like PCI, cardholder data, and sensitive authentication data. It explains why PCI security standards are important to protect payment card data and prevent fraud. The document outlines the six goals and twelve requirements of PCI-DSS, as well as introducing PA-DSS which focuses on developing secure payment applications. It provides instructions on determining an organization's PCI compliance level and selecting the appropriate Self Assessment Questionnaire.