See hard disk.

In computing, a storage device consisting of a rigid metal disk coated with a magnetic material. Data are read from and written to the disk by means of a unit called a disk drive. The hard disk may be permanently fixed into the drive or in the form of a disk pack that can be removed and exchanged with a different pack. Hard disks vary from large units with capacities of over 3,000 megabytes, intended for use with mainframe computers, to small units with capacities as low as 20 megabytes, intended for use with microcomputers.
A device containing one or more inflexible platters coated with material in which data can be recorded magnetically, together with their read/write heads, the head-positioning mechanism, and the spindle motor in a sealed case that protects against outside contaminants. The protected environment allows the head to fly 10 to 25 millionths of an inch above the surface of a platter rotating typically at 3600 to 7200 rpm; therefore, much more data can be stored and accessed much more quickly than on a floppy disk. Most hard disks contain from two to eight platters. See the illustration. Also called: hard disk drive. Compare floppy disk. hard-disk + prikaži više