Cod is the common name for the demersal fish genus Gadus, belonging to the family Gadidae. Cod is also used as part of the common name for a number of other fish species, and one species that belongs to genus Gadus is commonly not called cod.
Cod and other cod-like fish have been widely used as food through history. Other cod-like fish come from the same family (Gadidae) that cod belong to, such as haddock, pollock, and whiting.