Apple's device identifier for advertising. Requires explicit ATT opt-in on iOS 14 and later.

Google's Android Advertising ID. The equivalent of IDFA for Android devices.

The iOS permission prompt introduced in iOS 14 that requires users to opt in before their IDFA can be used for tracking.

Apple's privacy-preserving attribution framework for iOS, providing install and conversion signals without exposing individual user data.

Google's future framework for post-ID attribution solutions on Android.

Systems that track conversions and installs back to their originating ad source. The three main approaches are: SKAdNetwork for iOS (privacy-preserving, aggregated), GAID-based attribution for Android (device-level), and Probabilistic Attribution (fingerprint-based matching, increasingly restricted).

Probabilistic matching using device signals (screen size, OS, IP, etc.) to identify users without a device ID. Increasingly restricted by both Apple and Google.

Data collected directly by a brand or app from its own users.

Data collected by external vendors and merged with other sources for targeting.

Targeting based on the content or environment of an app or page, rather than user identity.

Privacy laws from the EU and the US respectively, protecting users from having their personal data used without consent.

A U.S. federal law requiring parental consent before collecting data from children under 13. Restricts behavioral targeting and persistent identifiers in child-directed apps. Also commonly used as a shorthand for audiences under 13.