Question about ratings

[Machforce1]

Foodie, I agree with you. That's sort of my reason for asking that question. When a rater, such as Parker, gives a relatively unknown, inexpensive wine a 91, and then scores a certain vintage Haut Brion a 93, is he saying that the unknown wine is nearly as good as the Haut Brion? Or is he saying the Haut Brion is good compared only to first growth Bordeaux of the same vintage? What exactly are they saying with these ratings? Or do they just use these things to pump certain Chateaux and vineyards?