Application Data & Files

Android uses a file system that's similar to disk-based file systems on other platforms. The system provides several options for saving app data:

• App-specific storage - internal storage to saving sensitive information that other apps should not be able to access.

• Shared storage - storage for files that the app shares with other apps, including media, documents, and other files.

• Preferences - storage for private, primitive data in key-value pairs.

• Databases - storage for structured data in a private database using the Room persistence library.

	Type of content	Access method	Permissions needed
App-specific files	App-specific files	From internal storage, getFilesDir() and getCacheDir() From external storage, getExternalFilesDir() and getExternalCacheDir()	Never needed for internal storage Not needed for external storage when your app is used on devices that run Android 4.4 (API level 19) or higher
Media	Shareable media files (images, audio files, videos)	MediaStore API	READ_EXTERNAL_STORAGE when accessing other apps' files on Android 11 (API level 30) or higher READ_EXTERNAL_STORAGE or WRITE_EXTERNAL_STORAGE when accessing other apps' files on Android 10 (API level 29) Permissions are required for all files on Android 9 (API level 28) or lower
Documents and other files	Other types of shareable content, including downloaded files	Storage Access Framework	None
App preferences	Key-value pairs	Jetpack Preferences library	None
Database	Structured data	Room persistence library	None

References

• Android Developers: Data and file storage overview