Hard Disk

The primary computer storage device, which spins, reads and writes one or more fixed disk platters. Hard drives are the storage medium in desktop and laptop computers as well as all servers and mainframes throughout the world.

They can also used in digital music players and a myriad of other portable and stationary computer-based devices. Although removable disks encased in cartridges use the same "hard" disk media and a similar drive technology, they are mostly called "removable drives" rather than hard drives.