App Specific Storage

// PRIVATE - no need for permissions here 
// private dir in internal storage:
Context.getFilesDir(); // system doesn't clean this memory, put sensitive user data here. Not even user can read this files
Context.getCacheDir(); // system will clear this when low on memory

// (app specific) private dir in "external"(readable by all apps with READ/WRITE_EXTERNAL_STORAGE_PERMISSION) storage
Context.getExternalFilesDir();
Context.getExternalFilesDirs(); // plural! As of KitKat it returns "external" directory folder, but also one from the SD card
Context.getExternalCacheDir();
Context.getExternalCacheDirs(); // same here
Context.getExternalMediaDirs(); // added in Lollipop, add here files you want to be read by medi scanner

// for game developers and in purpose of expension files
obb directory // shared across all users

// PUBLIC - survives app being uninstalled
// not deleted when "Cleare data and clear cache" is cleared in Settings
// (user specific) public user dir in "external" storage directory
Environment.getExterenalStorageDirectory() // root, kao C:\
Environment.getExterenalStoragePublicDirectory(String) // 

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