Geese are waterfowl of the family Anatidae. This group comprises the genera Anser (the grey geese) and Branta (the black geese). Chen, a genus comprising 'white geese', is sometimes used to refer to a group of species that are more commonly placed within Anser. Some other birds, mostly related to the shelducks, have "goose" as part of their names. More distantly related members of the family Anatidae are swans, most of which are larger than true geese, and ducks, which are smaller.
Textauszug zu Goose aus Wikipedia (Lizenz)