Magnetic head slides along the disk surface - deleting.

Head - The device that reads and writes the information-magnetic or optical-on the disk surface.

The increased density isn't because the process generates smaller magnetic grains on the disk surface.

The disk surface is also normally of high quality and is unlikely to shed its magnetic layer, at least not for several years.

Stiction was a phenomenon where the head would essentially molecular bond to the hard disk surface because they were both so smooth.

Because only laser light touches the disk surface, it theoretically does not wear out.

The energy emitted at the disk surface is in form of electromagnetic radiation.

And once it's going, then you're often able to stay out there over the disk surfaces.

The program cannot fix mechanical errors, of course, but it can mend almost anything else on the hard disk surface.

A longer and more thorough version of the short self-test, scans the entire disk surface, with no time limit.