data storage devices 
Electronic devices used to record or save data on a magnetic or optical medium.
hard disk drive
Device integrated into the computer that reads and writes data on the hard disk inside the case.
Rigid magnetic medium that is mounted on a central axis; its surface is divided into tracks and sectors on which data are written.
Device that converts the electric energy powering it into mechanical energy so that disks can rotate at several thousand revolutions per minute.
actuator arm motor
Device that converts the electric energy powering it into mechanical energy to move the actuator arm according to the computer’s instructions.
Device used to extract stored data from a disk or to write new data on a disk.
Movable arm bearing the read/write head; it moves the head across the surface of the disk.