I've found a few sources that state they used to be differentiated , mostly due to the color of the mold , but they are so close , that the names are now interchangeable , it's probably of no concern to the home cheese maker , as the results in cheese is probably undetectable to most.
In some scholarly articles they still differentiate between the two.
It is interesting to note that Candidum or Candida , is Latin for bright white , while Camemberti just denotes a fungus from the Camembert region of France , some forms of the mold are light grey , but the white molds were favored by cheese makers for their appearance.
Different variants of the same species ?
Linuxboy would know.
Regardless , I've always found Cams to be stronger tasting than Brie , could just be the ones available in my area though.