Defined on this site
- IDFA
- The IDFA, short for Identifier for Advertisers, is the advertising identifier on an Apple device. An app can read it only after the user gives permission through App Tracking Transparency. Without permission the value is all zeros.
- SKAdNetwork
- SKAdNetwork, often shortened to SKAN, is Apple's ad network API for measuring the success of ad campaigns while maintaining user privacy. The device attributes the install and later sends the ad network a delayed postback that names the campaign and never the user. It works without App Tracking Transparency permission.
- Crowd anonymity
- Crowd anonymity is the idea that a SKAdNetwork postback carries less detail when the crowd of similar installs is small. Apple relates its postback data tiers to relative crowd sizes. To ensure crowd anonymity, the device may limit the data in a postback, and Apple assigns every app download a postback data tier that sets how much is sent.
- ATT
- ATT, short for App Tracking Transparency, is the Apple framework an app must use to ask a user's permission before tracking them or accessing the device's advertising identifier. It applies in iOS 14.5, iPadOS 14.5 and tvOS 14.5 or later.