A hard disk drive (HDD), commonly referred to as a hard drive, hard disk or fixed disk drive,Other terms used to describe hard disk drives include disk drive, disk file, DASD (Direct Access Storage Device), fixed disk, CKD disk and Winchester Disk Drive (after the IBM 3340). is a non-volatile storage device which stores digitally encoded data on rapidly rotating platters with magnetic surfaces. Strictly speaking, "drive" refers to a device distinct from its medium, such as a tape drive and its tape, or a floppy disk drive and its floppy disk. Early HDDs had removable media; however, an HDD today is typically a sealed unit with fixed media.[LINK: http://computer.howstuffworks.com/hard-disk1.htm] How Hard Disks Work, howstuffworks.com HDDs were originally developed for use with compu