What is SharedPreferences in Flutter?

SharedPreferences is a Flutter plugin for persisting simple key-value data on the device. It supports bool, int, double, String, and List<String>. It uses NSUserDefaults on iOS and SharedPreferences on Android under the hood. Usage: final prefs = await SharedPreferences.getInstance(); prefs.setString("token", token);. It is asynchronous and persists data across app restarts. Do not store sensitive data like passwords here — use flutter_secure_storage instead.