Avatar draws on four classical elements for its bending arts (rather than the 5 Classical Chinese Elements): Water, Earth, Fire and Air. Although each has its own variation, most ancient philosophies incorporate these four elements in some way, including the classical Hindu, Buddhist, Greek and Japanese elemental traditions.
In the show’s opening, each element is accompanied by 2 Chinese characters — an ancient Chinese seal script character of the element on the left, along with a more modern Chinese character of the corresponding attribute on the right:
Water (水) is associated with "" (Chinese: 善; pinyin: shàn), which means "benevolent" or "adaptive."
Earth (土) is associated with "" (traditional Chinese: 強; simplified Chinese: 强; pinyin: qiáng), which means "strong."
Fire (火) is associated with "" (Chinese: 烈; pinyin: liè), which means "intense" or "ferocious."
Air (气) is associated with "" (Chinese: 和; pinyin: hé), which means "peaceful" or "harmonious".
When read from right to left in the way Chinese characters used to be written, they form actual Chinese phrases — namely, the "benevolent water", the "strong earth", the "intense fire" and the "harmonious air".
Water Bending
Earth Bending
Fire Bending
Air Bending