What is a data breach: A data breach is an incident in which sensitive, protected, or confidential information is accessed, disclosed, or stolen without authorization. This includes personal data such as names, Social Security numbers, financial details, or medical records. Breaches typically occur through cyberattacks, system vulnerabilities, or human error, and can lead to identity theft, financial loss, or reputational harm for individuals and organizations. Authorities, including the Federal Trade Commission, emphasize immediate reporting and mitigation steps.