Floppy disks have just about disappeared from the computer world, but even when they were common it was only in the early years that they were literally floppy. The fact that a 3 1/2″ diskette is enclosed in a hard plastic case should not lead you to call it a “hard disk.” That’s a high-capacity storage medium like the main disk inside your computer on which your programs, operating system, and data are stored.

See also drive/disk.