Difference between EARS, EADS and EVDS disks?

HI I wanto to buy 1500GB disk, but there are three types of them(EVDS, EADS, EARS) and no explanation. Can anybody tell me the difference?

there is no wd1500ears as far my knowledge

WD1500EVDS — >> WD AV-GP

WD1500EADS — >> WD CAVIAR GP

ears use new format technique

eads & evds use traditional algorithms

I’m not really familiar with EARS and EADS. What exactly does the EADS or EARS actually mean because I’m not to sure I only want this hard drive to back up everything on my computer should I buy it? Please help thank you

For an explanation of the letters in the drive model designation, see:

http://www.wdc.com/en/library/2579-001028.pdf