A couple of days ago, I voted to close this qestion as off-topic.
It seems I'm still the only one who think it's off-topic, probably the question has been removed from the review-queue by another user.
The question is, as far as I see, about terminology and not related with Ubuntu, so my question is:
What makes this question on-topic?
cliand the difference between them are nothing special for Ubuntu but valid for all operating systems, of course also for Ubuntu. I think that's the point, close vote retracted.