IDFA
IDFA stands for Identifier for Advertising, a device‑level random identifier assigned by Apple to iOS devices to enable advertisers to track and profile users for advertising and attribution.
It is used to deliver personalized ads, measure ad performance, frequency capping, and cross‑app and cross‑site
Privacy changes have significantly affected how the IDFA is used. Since iOS 14, App Tracking Transparency requires
Impact and usage continue to evolve in response to policy and user expectations. While the IDFA remains
Related identifiers include the Identifier for Vendor (IDFV), which is scoped to apps from the same vendor.