Storage forum: Hard drive S.M.A.R.T. question - "Power On Hours Count"

I recently downloaded a program called SpeedFan, which in addition to showing a number of temperatures & fan speeds, has a S.M.A.R.T. analysis function, which takes me to this web site:
http://www.hddstatus.com/hdrepanalysis.php
The Web page states:

Your hard drive is a
WDC WD1600JB-00GVA0 with firmware 08.02D08

Attribute : Power On Hours Count
Current : 94
Raw : 4779
Overall : Watch
Warning : Power On Hours Count is below the average limits (96-100).

NOTE : your hard disk Power On Hours Count attribute current value (94) is below the normal range (96 - 100) reported for your specific hard disk model. Basically your hard disk was powered on for more than the maximum time the average user did. This means that either all of the reports collected are from hard disks that were not powered on for too long (this is realistic for recent models) or that your hard disk is becoming old. Usually this is not considered as a pre-failure advisory, but you should check whether you want to replace the hardware or keep an eye on its performances over time.

The overall fitness for this drive is 96%.
The overall performance for this drive is 100%.

The "meter" next to it has the indicator line all the way towards the red end of the red-to-green color bar.



I've looked around, but I can't find a straight answer to my question, WHAT is the power on hours count? Is it how many hours the hard drive has been on? If so, what is wrong with 94 hours? People turn their computers on for 10 hours, sometimes ... some leave them on all the time to function as a server.
Or, is that to mean that it's only going to last for 94 hours? If so, how do computers' hard drives last for years, as servers?


Anyway, the message next to 94 states that normal is
96 >= normal >= 100


What is with this, and should I be worried?

Again, I have a
WDC WD1600JB-00GVA0 with firmware 08.02D08