A mechanical unit that holds a disk, which could be a floppy disk, CD-ROM or a hard disk, and responds to the instructions of a controller card. The drive will have a motor that spins the disk and an access head that can be positioned over the disk. The access head can, in the case of a floppy or hard disk, write or read data from the surface of the disk. In the case of a CD-ROM, the access head uses a tiny laser to read the holes etched in the surface of the disc.
