What changes in the new feature The new feature makes a big change when it comes to app developers tracking user data to sell it to advertisers. Before iOS 14.5, developers could use a number of tools to track user data from an app and sell those data to advertisers who would then use that data to create a user profile to target advertisements towards a specific user. It created a chain, as the advertisers, in turn, could sell those advertising opportunities to other businesses to focus on specific user or market segments. It was not like users had no choice when it came to tracking their data before iOS 14.5. Users could still stop an app from tracking their data. But what the new 'App Tracking Transparency' feature does, is that it puts the choice up front, and forces the developers to give users a very specific choice before even launching the app.