disk drives

Devices that, using an access mechanism under program control, enable data to be read from or written on a spinning magnetic disk, magnetic disk pack, floppy disk, or optical disk media. "Disk drives" may be used to refer to devices that use either fixed or removable media. To refer specifically to fixed, large-capacity magnetic disk drives used to store computer data, use "hard drives." To refer to the fixed disk itself, rather than the mechanism it is a part of, use "hard disks."