The swan is a large bird and a large swimming bird, with a body length of about 1.5m and a weight of more than 10kg. The plumage is white, the mouth is mostly black, and the upper mouth to the nostrils is yellow. Their necks are long, about half their body length.

Swans often swim with their necks outstretched and their wings pressed against each other. Because of their graceful posture, swans have been the embodiment of beauty and grace throughout the ages.

Swans maintain a rare "mate for life". During wintering, they both feed and rest in pairs. While the female swans are laying eggs, the male swans stand beside them. When it encounters an enemy, it flaps its wings to meet the enemy and fights bravely. Not only do they help each other during the breeding season, but they also usually come in pairs, and if one dies, the other will live alone for life.

The swan is the largest waterfowl in the Anseriformes Anatidae, with 7 or 8 species. 5 species live in the northern hemisphere and are all white with black feet. There are mute swans, trumpet swans, loud swans, Biek's swans, Yankowski's swans, and whistle swans.

There are black swans and black-necked swans in the southern hemisphere. Swans are graceful in shape, with long necks, solid bodies and large feet. They are solemn when gliding in the water. When flying, they stretch their long necks and flap their wings slowly. When flying over the winter, they form a diagonal or "human"-shaped queue at a high altitude. Other waterfowl are not as fast as swans, either in water or in the air.