The Amazon Rainforest, also known as Amazonia, the Amazon jungle or the Amazon Basin, encompasses seven million square kilometers (1.7 billion acres), though the forest itself occupies some 5.5 million square kilometers (1.4 billion acres), located within nine nations. The Amazon represents over half of the planet’s remaining rainforests and comprises the largest and most species-rich tract of tropical rainforest in the world. The Amazon River is the largest river in the world by volume, with a total flow greater than the top ten rivers worldwide combined. It accounts for approximately one-fifth of the total world river flow and has the biggest drainage basin on the planet. Not a single bridge crosses the Amazon.

The Amazon River Basin is home to the largest rainforest on Earth. The basin -- roughly the size of the forty-eight contiguous United States -- covers some 40% of the South American continent and includes parts of eight South American countries: Brazil, Bolivia, Peru, Ecuador, Colombia, Venezuela, Guyana, and Suriname, as well as French Guiana, a department of France.

Reflecting environmental conditions as well as past human influence, the Amazon is made up of a mosaic of ecosystems and vegetation types including rainforests, seasonal forests, deciduous forests, flooded forests, and savannas. The basin is drained by the Amazon River, the world's largest river in terms of discharge, and the second longest river in the world after the Nile. The river is made up of over 1,100 tributaries, 17 of which are longer than 1000 miles, and two of which (the Negro and the Madeira) are larger, in terms of volume, than the Congo (formerly the Zaire) river. The river system is the lifeline of the forest and its history plays an important part in the development of its rainforests.