Saving file information is used in many aspects of game development. We use it to save high scores and game settings, such as sound on/off, locking/unlocking levels, and so on. It is not necessary to have these features, but as they are good to have, maybe you'd like to include them in your applications.

In Corona SDK, applications are sandboxed; this means that your files (application images, data, and preferences) are stored in a location that no other application can access. Your files will reside in an app-specific directory for documents, resources, or temporary files. This restriction is related to the files on your device, not when you are coding on your Mac or PC.