Rainforests are forests characterized by high rainfall, with definitions setting minimum normal annual rainfall between 1750 mm and 2000 mm.

Rainforests are home to two-thirds of all the living animal and plant species on the planet. It has been estimated that many hundreds of millions of new species of plants, insects and microorganisms are still undiscovered. Tropical rain forests are called the "jewels of the earth", and the "world's largest pharmacy" because of the large amount of natural medicines discovered there.

The rainforest is divided into five different parts, each with different plants and animals, adapted for life in that particular area:
Emergent layer
Canopy layer
Understory layer
Shrub Layer
Forest floor

Rainforests support a very broad array of fauna including mammals, reptiles, birds and invertebrates. Mammals may include primates, felids and other families. Reptiles include snakes, turtles, chameleons and other families. Birds include such families as vangidae and Cuculidae. Dozens of families of invertebrates are found in rainforests. More than half of the world's species of plants and animals are found in the rainforest. This amounts to over 5 million species of plants and animals.