Another important difference between a hard disk drive and a floppy drive is that the read write heads of the hard disk drive do not touch the surface of the disk the way they do in a floppy drive. Hard disks, like the one shown in Figure 1. 14, hold much more data than a floppy disk. An IBM PC floppy disk can hold approximately 1.44MB of data. Hard disks hold twenty megabytes or more of data.
Hard disks are high precision, delicate instruments.
They must be handled with care to avoid head crashes, which occur when the read write head of a hard drive comes in contact with the rigid platter. If this happens, all of the data on the disk will probably be lost. In most cases, the platters in a hard drive are not removable. Therefore, the data on a hard disk cannot usually be carried from one computer to another. For this reason, hard disks are sometimes called Winchesters.