Which data storage mechanism — UserDefaults or KeyChain — retains information after the app is reinstalled?

KeyChain retains data after deleting and reinstalling the app, whereas UserDefaults does not.

• UserDefaults stores settings and data in the app's container. When the app is deleted, all UserDefaults data is removed.
• KeyChain is a secure storage designed for storing confidential information (passwords, tokens). Data in KeyChain remains even after the app is deleted, unless the device is changed or the KeyChain is manually cleared.

Therefore, to preserve data across app reinstalls, KeyChain should be used.