Data masking is a method used in data security to protect sensitive information by altering the original data in a dataset, making it unreadable or less sensitive while maintaining its usability for testing, development, and analytics. This technique involves substituting sensitive data with random characters or altered values, ensuring that the original data cannot be accessed by unauthorized individuals. Data masking is often applied to protect personal identifiable information (PII), financial records, and other confidential information to enable organizations to safely share and utilize data while maintaining privacy and compliance with regulatory standards.