When an app is installed, the system gives it its own per-user data stores for settings and files. You don't need to know where or how this data exists, because the system is responsible for managing the physical storage, ensuring that the data is kept isolated from other apps and other users. The system also preserves the contents of these data stores when the user installs an update to your app and removes the contents of these data stores completely and cleanly when your app is uninstalled.