The Amazon rainforest is the world's largest rainforest by a significant margin. Compared to the Congo rainforest, the second largest, the Amazon is more than twice its size in terms of its tree cover extent, and more than three times larger in terms of primary forest area. In fact, over half of all tropical primary forest area on the planet is located in the amazon.
Primary forest refers to the area of the forest that remains largely undisturbed by human activity, whereas the total tree cover extent refers to both the primary and
secondary forest, which includes areas that have been used for commercial purposes such as logging or palm oil production, or reforested areas of conservation.
In some rainforests in Southeast Asia and South America, less than 50 percent of the forest area is made up of primary forest area due to human activity. This figure is lowest in the Atlantic Forest in Brazil, Paraguay, and Argentina, where the figure is just over 10 percent, and Paraguay is the country that has seen the
largest relative decrease in its total forest area over the past three decades.