As we saw in the previous chapter, internal storage is a good way to save private data on a device. Every Android application has a corresponding internal storage directory in which private files can be created and written to. These files are private to the creating application, and as such cannot be accessed by other applications on the client device. As a rule of thumb, if data should only be accessible by your application and it is reasonably possible to store it in internal storage, do so. Feel free to refer to the previous chapter for a refresher on how to use internal storage.