I have read at various times that when digitized files - i.e. data held on hard drives, DVDs etc.- are copied there no loss in quality. I have however also read that there is "virtually" no loss in quality. If the word "virtual" means "almost" it means that if a DVD that contains a film is copied then the copy is almost (but not quite) as good as the original.

So is there no loss in quality or almost no loss in quality. I would like to know. I would have though that provided there are no errors in the copying process, which would be reported by applications such as Nero, then the copy would be exactly the same and as good as the original.

There is always a loss in quality when going from Analog to Digital.
But it's so small that you can't tell.

But if you copy from Digital to Digital (Hard drive to DVD or HD to Flash Drive, etc) there is no loss.

Of course when you buy a DVD they use software to kind of negate the affects of Generation Loss.

Either way once it's digital and in your possession the copy won't get any worse. ^^