Like an audio tape, a floppy disk can be erased and reused over and over again. A hard disk drive contains circular platters of highly polished steel which can also store computer information and can be erased and reused. They are protected from damage by being contained within vinyl or plastic sleeves which inhibit dust or fingerprints from coming into contact with the disk's surface. In order to work, floppy disks are inserted into a disk drive which is a device which rotates the disk much as a record player rotates a record. A hard disk drive works in essentially the same manner, however, its steel disks are permanently contained inside a sealed cabinet rather than being inserted and removed by the computer user.
Hard disks can store much more information than floppy disks.