You can save data in device’s internal storage as well. Data stored in Internal storage will be considered as a private data for your application and will not be accessible by other applications. Also, once your app gets uninstalled, this data automatically gets removed.
Shared preference provides you a framework to save your data in terms of key and value. You can only store primitive type data in SharedPreference (booleans, floats, ints, longs, and strings). This data will persist even after the application is killed.