The main difference between Turbot and Halibut is that the Turbot is a species of fish and Halibut is a common name, for edible fishes
The turbot (Scophthalmus maximus) is a relatively large species of flatfish in the family Scophthalmidae. It is a demersal fish native to marine or brackish waters of the Northeast Atlantic, Baltic Sea and the Mediterranean Sea. It is an important food fish. Turbot in the Black Sea have often been included in this species, but are now generally regarded as separate, the Black Sea turbot or kalkan (S. maeoticus). True turbot are not found in the Northwest Atlantic; the “turbot” of that region, which was involved in the so-called “Turbot War” between Canada and Spain, is the Greenland halibut or Greenland turbot (Reinhardtius hippoglossoides).
Halibut is a common name principally applied to the two flatfish in the genus Hippoglossus from the family of right-eye flounders. Less commonly, and in some regions only, other species of flatfish are also referred to as being halibuts. The word is derived from haly (holy) and butte (flat fish), for its popularity on Catholic holy days. Halibut are demersal fish and are highly regarded as a food fish.
A species of flatfish native to Europe (ver=161026, earlier ver=161026).
Any of various other flatfishes of family Scophthalmidae that are found in marine or brackish waters.
A large flatfish of the genus Hippoglossus, which sometimes leaves the ocean floor and swims vertically.