(1) See
USB drive and
external drive.
(2) A disk or disk cartridge that is inserted into the drive for reading and writing and removed when not required. CD, DVD and Blu-ray discs are optical examples.
Removable Magnetic Disks (Obsolete)
Prior to the widespread use of portable USB hard drives, various removable magnetic disk cartridges were available for backup and transport. They were popular in the 1990s because of their increasing storage capacity. See
Zip disk,
REV disk,
magnetic disk and
optical disc.
Removable Magnetic Disk Cartridges
In the 1980s, SyQuest pioneered the removable magnetic disk for personal computers. Ranging from 44 to 270MB, they seem pitifully small today. See
SyQuest.