The birds referred to as fowl belong to one of two orders, namely the gamefowl or landfowl (Galliformes) and the waterfowl (Anseriformes). Interestingly, studies of anatomical and molecular similarities suggest these two groups were close evolutionary relatives; together, they form the fowl clade which is scientifically known as Galloanserae. This clade has been supported by Retrotransposon presence/absence data as well. "Poultry", on the other hand, is a term for any kind of domesticated bir… (More on Fowl)