The mighty Amazon Rainforest also known as Amazonia or Amazon Jungle, is home to the largest standing tropical rainforest on Earth therefore its is world’s richest and most varied biological reservoir for life itself [5,500,000 km2 (2,100,000 sq mi)], containing several million species of insects, plants, birds, and other forms of life, many still unrecorded by science. The rainforest has been in existence for at least 55 million years, this neotropical evergreen rain forests evolved into a mosaic of ecosystems and vegetation types: seasonal forests, deciduous forests, flooded forests, and savannas.
This vast region belongs to nine South American nations: Brazil, with 60%, Peru with 13%, Colombia with 10%, and with minor amounts in Venezuela, Ecuador, Bolivia, Guyana, Suriname and French Guiana.
The Amazon Basin is composed by the drainage system of the Amazon River and its tributaries that stretch out through a dense tropical forest, this is in fact the largest tropical rainforest on our planet; these basin covers some 40% (6,915,000 km2 (2,670,000 sq mi) of the South American continent and includes parts of South American countries mentioned above.
The Amazon River has the largest drainage basin in the world, it is definitely the largest in South America, its the world's largest river in terms of discharge ( 209,000 m³/s or 7,381,000 cu ft/s), and the second longest river (6,453 km ) in the world after the Nile. The river is made up of over 1,100 tributaries, 17 of which are longer than 1000 miles,
The Ucayali-Apurímac river system is considered the main source of the Amazon, with its main headstream being the Carhuasanta glacial stream flowing off the Nevado Mismi mountain in Peru.
The width of the Amazon is between 1.6 and 10 kilometres (1.0 and 6.2 mi) at low stage but expands during the wet season to 48 kilometres (30 mi) or more. The river enters the Atlantic Ocean in a broad estuary about 240 kilometres (150 mi) wide. The mouth of the main stem is 80 kilometres (50 mi).