Rainforests are a type of forest ecosystem found mainly in the tropics and characterised by the heavy rainfall they receive (between 1750 and 2000mm per year).
Rainforests have four layers: the tallest trees are called the emergent layer, then there is the canopy, which consists of the leaves and branches of the other tall trees, followed by the shady understorey of small shrubs and young trees and, finally, the forest floor.
Rainforests contain over half the species of plants and animals on Earth and are the source of many useful products, including chocolate, timber, rubber, different medicines and fruit such as pineapples.
The Rainforests moderate our climate and act as the whole Earth's lungs, because of the photosynthesis of the trees.
We are converting huge areas of rainforest for agriculture.
If the Rainforests continue to be destroyed, most life on Earth, including humans, will be at risk of extinction, because of falling oxygen levels.