Implications of iOS 14.5 on Tracking
Identifier Collection for ad tracking will require an opt-in by the user via the App Tracking Transparency prompt.
Without App Tracking Transparency framework opt-in, you cannot collect any identifier for ad tracking such as: IDFAs, fingerprints IDs, user’s location, network connection, session ID, device graph identifiers, etc.
SKAdNetwork framework acts as a new attribution system for paid advertising channels.
Apple introduced SKAdNetwork to help advertisers track performance for advertising channels without having to obtain opt-ins from the users. SKAdNetwork will not share any identifiers with both advertising channel and the attribution solution, however as it provides granular event data, advertising channels and attribution solutions can aggregate the attribution results into a report.