What is a mechanical hard disk and is it useful?

Mechanical hard disk is a traditional common hard disk, which is mainly composed of disk, magnetic head, disk spindle, control motor, magnetic head controller, data converter, interface and cache.

The magnetic head can move along the radial direction of the disk, and the disk rotates at a high speed of several thousand revolutions per minute, so the magnetic head can be positioned at the designated position of the disk to read and write data. Information is written on the disk by the electromagnetic current of the magnetic head close to the magnetic surface, and information can be read in the opposite way. Hard disk is a precision device, and dust is its enemy, so the air entering the hard disk must be filtered.