Portable data storage medium that can be added to or removed from a computing device or network.
Note: Examples include, but are not limited to: optical discs (CD, DVD, Blu-ray); external / removable hard drives; external / removable Solid State Disk (SSD) drives; magnetic / optical tapes; flash memory devices (USB, eSATA, Flash Drive, Thumb Drive); flash memory cards (Secure Digital, CompactFlash, Memory Stick, MMC, xD); and other external / removable disks (floppy, Zip, Jaz, Bernoulli, UMD).
See also portable storage device.
Sources:
CNSSI 4009-2015