Device
A device provides access to volumes, which are used to store backups. A single device may, over time, allow access to different volumes. For example, different tapes may be loaded into a single tape drive; or though some shuffling of symlinks by chg-disk (see amanda-changers(7), a particular VFS device may be configured to point to different vtapes.
See also: FAQ:What's the difference between a device and a changer? Between tapedev and tpchanger?