Floppy Disk, in computer science, a round, flat piece of Mylar coated with ferric oxide, a rustlike substance containing tiny particles capable of holding a magnetic field, and encased in a protective plastic cover, the disk jacket. Data is stored on a floppy disk by the disk drive's read/write head, which alters the magnetic orientation of the particles. Orientation in one direction represents binary 1; orientation in the other, binary 0. Typically, a floppy disk is 5.25 inches in diameter, with a large hole in the center that fits around the spindle in the disk drive. Depending on its capacity, such a disk can hold from a few hundred thousand to over one million bytes of data. A 3.5-inch disk encased in rigid plastic is usually called a microfloppy disk but can also be called a floppy disk
Disk Drive, in computer science, an electromechanical
device that reads from and writes to disks. The main components of a disk
drive include a spindle on which the disk is mounted, a drive motor that
spins the disk when the drive is in operation, one or more read/write heads
that perform the actual reading and writing, a second motor that positions
the read/write heads over the disk, and controller circuitry that synchronizes
read/write activities and transfers information to and from the computer.
Two types of disk drives are in common use: floppy-disk drives and hard-disk
drives. Floppy-disk drives are designed to accept removable disks in either
5.25-inch or 3.5-inch format; hard-disk drives are faster, high-capacity
storage units that are completely enclosed in a protective case. When a
computer system has more than one disk drive, each is referenced by its
own name or number—for example, drives A: and C: under MS-DOS or drives
0 and 1 on the Apple Macintosh.