Verbatim External Hard Drive - Manual (Page 5)

How it works
All hard disks use rotating platters
(disks) which spin at a constant RPM.
Each platter has a smooth magnetic
surface on which your digital data
is stored. Information is written to
the disk by applying a magnetic
fi eld from a read-write head that
fl ies very close over the magnetic
surface. The magnetic medium
(fi lm) on the disk surface changes its
magnetization in microscopic spots
(bits) due to the head’s write fi eld.
The information can be read back by
a magnetoresistive (MR) read sensor
which is part of the same head
structure on the trailing end of the
fl ying slider. The read sensor detects
the magnetic fl ux eminating from the
bit transitions passing underneath
it through a small change of the MR
sensor’s electric resistance. Magnetized Data on Disk
Motion of Suspension and Head
Tracks
Head
Disk
Rotation
Disk