Organizations in the World of Avatar

Council of Elders
The Council of Elders were the leaders of the Air Nomads. Each of the Air Temples had its own council of Head Monks and/or Nuns, their members being both the political and the religious authorities. The Northern and Southern councils were composed of five head monks each, and the Eastern and Western councils were composed of five head sisters each.

Military of the Water Tribes
The Military of the Water Tribe is a group of organizations protecting the Water Tribes. It is divided between the Northern Water Tribe and the Southern Water Tribe. Chain of command is not very well defined. There is no overall military commander of the Water Tribe, command being divided between the North and South. It is clear however that the Chiefs of the two tribes have the overall command of their respective tribal militia.

Military of the Earth Kingdom
The Military of the Earth Kingdom is the military organization responsible for the defense of the Earth Kingdom. It consists of an Army, a Navy and several Special Forces. It wields considerable power, having held off Fire Nation assaults for a century. The Earth King is the constitutional overall commander, although at times his actual power has been very limited. The main commanding authority is the Council of Five, a council of five senior generals who oversee any war effort from Ba Sing Se.

Council of Five
The Council of Five is the highest authority in the Earth Kingdom military, and oversees the country's entire war effort against the Fire Nation. The council is headed by General How, the commanding officer of the military. Among the council members is General Sung, who defends Ba Sing Se's Outer Wall from attack. The other three generals were briefly seen, but weren't named.

Dai Li
The Dai Li were the secret police of Ba Sing Se who worked to capture, interrogate and imprison political dissidents. They were created by Avatar Kyoshi hundreds of years ago with the aim of "protecting the cultural heritage of Ba Sing Se".

Kyoshi Warriors
The Kyoshi Island Warriors are an all-female group of fighters led by Suki on Kyoshi Island. Their individualities have been greater expanded since the first season. In "The Warriors of Kyoshi", all of the other warriors look exactly the same, but in "Appa's Lost Days" they all have different hairstyles and headdresses.

Jasmine Dragon
The Jasmin Dragon is a tea shop owned by Iroh and Zuko. This tea shop is the reason why they were moved to upper class section in Ba Sing Se. This is the place where the last scene in the Avatar: The Last Airbender is shown.

Order of the White Lotus
The Order of the White Lotus is an ancient secret society that transcends national boundaries. The order is about philosophy, beauty and truth. They are devoted to the sharing of ancient knowledge and philosophy across national and political divides. Formed centuries ago by the wisest scholars from all over the world, the Order began as a club where these ancient masters could challenge one another on the Pai Sho table. They derived their name from the White Lotus tile used in Pai Sho, a key element in their favored strategy in the game. Iroh is the Grand Lotus of the order.

Team Avatar
The Team Avatar is composed originally of Aang, Katara, and Sokka. Their mission is to save the world from the Fire Nation. They travelled from the Southern Water Tribe to the Fire Nation. They started their journey when they found Aaang in the iceberg. As their journey continues, they find an earthbending teacher for Aang, named Toph. In book 3, more are added such as Suki and Zuko. They are successful in completing the mission in the show's finale Sozin's Comet.