what's the difference between android internal storage and external-private storage?

Question

I have read the android official documentation regarding android storage.

I understand there are:

1) internal storage: which is app-private. deleted when the app is removed. cannot be accessed by user nor other apps.

2) external storage -

2.a) private: app-private. deleted when the app is removed. cannot be accessed by user nor other apps.

2.b) public: the user and other apps can access and even edit.

from the official documentation:

Saving files that are app-private

If you are handling files that are not intended for other apps to use (such as graphic textures or sound effects used by only your app), you should use a private storage directory on the external storage by calling getExternalFilesDir(). This method also takes a type argument to specify the type of subdirectory (such as DIRECTORY_MOVIES). If you don't need a specific media directory, pass null to receive the root directory of your app's private directory.

So what is the difference between (1) and (2.a) ?

Answer 1

So what is the difference between (1) and (2.a) ?

There is no 2.a that meets your description. There is app-specific external storage that is removed on an uninstall, though the user and other apps can certainly get at it. Hence, it is not app-private.

You may wish to read some recent blog posts that I wrote that cover internal storage and external storage.

Answer 2

1. external storage means a space for applications and files
2. private means space for system files