Time Machine is the backup mechanism of macOS, the desktop operating system developed by Apple. The software is designed to work with both local storage devices and network-attached disks, and is commonly used with external disk drives connected using either USB or Thunderbolt. It was first introduced in Mac OS X 10.5 Leopard, which appeared in October 2007 and incrementally refined in subsequent releases of macOS. Time Machine was revamped in macOS 11 Big Sur to support APFS, thereby enabling "faster, more compact, and more reliable backups" than were possible previously.

MobileMe is a discontinued subscription-based collection of online services and software offered by Apple Inc. All services were gradually transitioned to and eventually replaced by the free iCloud, and MobileMe ceased on June 30, 2012, with transfers to iCloud being available until July 31, 2012, or data being available for download until that date, when the site finally closed completely. On that date all data was deleted, and email addresses of accounts not transferred to iCloud were marked as unused.