|Noun||1.||removable disk - a hard disk that can be removed from the disk drive; removal prevents unauthorized use|
|(storage)||removable disk - A type of magnetic disk, or possibly
magneto-optical disk which is not permanently attached to
the disk drive (not a fixed disk) but which can be taken
out and replaced, allowing many disks to be used in the same
Floppy disks are removable disks but the term is not commonly used for them but mostly for hard disks in suitable cartridges such as those made by Syquest, Iomega and others.
Removable disks have become popular on microcomputers in the 1990s since they offer a cheap way of expanding disk space, transporting large amounts of data between computers and storing back-ups. The concept is not new however, removable disk packs were common on minicomputers such as the PDP-11 in use in the 1970s except that the drives were the size of washing machines and the disk packs as big as car wheels.