Explain how files can be identified as entities on the magnetic surface?

Data is stored on a hard disk drive as a result of magnetism. A file or data is represented in bits on a disk, with 1 representing a magnetized entity and 0 for an unmagnetized surface.

Explanation:

A hard disk drive (HDD) is an electro-magnetic tool for storing data in computing. It is made of moving parts like a platter and read/write head for reading and writing data to the disk.

To read or write data on a disk, the platter spins at a very high speed ( 5000 RPM to 10000 RPM), and the head, at the right surface,  writes or reads a bit 1 as a magnetized surface and 0 as unmagnetized.