Learn more about Apple ID. If you use a different Apple ID for iTunes and iCloud, and want to restore from a backup, first enter your Apple ID for iCloud. After your device restarts, you'll be asked to enter the Apple ID that you use with the iTunes Store, App Store, or iBooks Store.
File system repository. The file system repository allows access to files which have been uploaded (e.g. via FTP) into designated folders on the server. A file system repository may be available site wide for everyone or within an individual course (set up by admin) or for an individual administrator.
What is a RAR file. RAR is the native format of WinRAR archiver. Like other archives, RAR files are data containers, they store one or several files in the compressed form. After you downloaded RAR file from Internet, you need to unpack its contents in order to use it.