A rainforest is a dense, tropical forest characterized by high rainfall, usually exceeding 100 inches annually. These ecosystems are home to a vast array of plant and animal species, many of which are not found anywhere else on Earth. The warm, humid climate supports towering trees, vibrant flowers, and a rich understory of shrubs and ferns. Rainforests play a crucial role in regulating the Earth's climate and are often referred to as the "lungs of the planet" because they produce significant amounts of oxygen. They are primarily located near the equator, with notable examples including the Amazon Rainforest in South America and the Congo Rainforest in Africa.