Geese are waterfowls of the family Anatidae. This group includes Anser and Branta. Chen, a genus of "white geese," is sometimes used to refer to a group of species more common in anser. Some of the other birds most associated with scheckled also use "geese" as part of their name. Swan is the distant member of an family, most of which are bigger than the real goose, while duck is smaller.

The three living genera of real geese are: geese, grey geese (including grey geese) and domestic geese; Chen, white geese (usually included in anser); and black geese, such as Canadian geese.

For the time being, only two genera of "geese" will be placed in anserinae. They may belong to the Aesculus, or they can form a subfamily of their own: ceropsis, Cape Baren geese and cnemiornis, prehistoric New Zealand geese. These geese, or coscroba swans more like geese, are close relatives of the real geese.

Real goose fossils are hard to classify. It can be said that their fossil records are very dense, especially in North America, and they comprehensively record many different kinds of real geese that existed about 10 million years ago since Miocene. Anser atavus, properly named about 12 million years ago, has more quasi forms than swans. In addition, some geese like birds have also been found in the sub fossil remains found on the Hawaiian Islands.

Geese are monogamous and live all year round. However, unlike most other permanent monogamous animals, they are territorial only during the short nesting season. Paired geese dominate and feed more, two factors that make them younger.