Ad data refers to the information collected and used by advertisers and digital platforms to deliver targeted advertisements to users. This data can include browsing history, recent interactions with ads, demographic details, device information, location, and user preferences or settings. Ad data helps companies personalize ad experiences, measure campaign effectiveness, and optimize marketing strategies. However, the collection and use of ad data raise privacy and security concerns, as unauthorized access or misuse can expose sensitive personal information. Regulations like GDPR and CCPA aim to govern how ad data is collected, stored, and shared, ensuring users have more control over their personal information.