Function of setting for APPS USING ICLOUD

What is the fuction of the toggle switches for apps under "APPS USING ICLOUD" in Settings >  Apple ID > iCloud?  It is not  to turn on backup for the settings of an app and for the documents created in the app and stored on the device.  The backup function is activated for individual apps in Settings > Apple ID > Manage Storage > Backups > This iPad > "CHOOSE DATA TO BACKUP."  Or am I incorrect?