Apple's App Tracking Transparency

Apple’s App Tracking Transparency is a privacy feature released in iOS 14 requiring apps to obtain permission from a user before collecting information from their activity across other apps. (Apple Support). This feature changes user data collection from being automatically opted-in to being automatically opted-out.

This new feature is one of many steps Apple has taken to increase user privacy and trust across their devices. Other measures include social widget tracking prevention, privacy reports, intelligent tracking prevention, and fingerprinting defense.