
 Originally Posted by 
joserizal
					 
				 
				what kind of HDDs sir? 
basically, HDD use optics to read and write.
DVDs also.
			
		 
	 
 Unfortunately, they don't.  If you read the link that I posted about giant magnetoresistance, then you will know.  In a way, they are similar, but everything is magnetic even information is magnetic.  Optical storage link DVDs rely on optics for writing information.  Information is physically written by the laser as bit line.  Reading the information would still use lasers and measurement of the scattering of the reflected laser beam.  They are similar but are different in nature. 

 hehehe