When you pass the first layer of fun animation and jokes, we can see the four nations each represent a specific aspect of Asian culture: the Fire Nation represents imperial Japan, the Earth Kingdom represents Communist China, the Northern and Southern Water Tribes represent indigenous people, and the Air Nomads

Airbenders emphasize intuition and imagination; to an airbender, there is always another path to take, as air flows wherever it can. This makes airbending the most dynamic of all the bending arts, and air itself is considered to be the element of freedom.