Mobile apps rely on an IDFA (which is something very similar to a cookie) when it comes to tracking users. Before iOS 14, tracking could just happen without any additional steps, allowing apps to easily identify and track users. Not only did this help target ads, but it let apps know if the user made a purchase, giving them important data. . Now, due to changes implemented with iOS 14, apps will need permission to track users with an IDFA. If the use of an IDFA is denied, it will prevent apps from collecting important data. Follow the link to read the details. https://penpath.com/blog/what-ios-14-means-for-tracking/