A rainforest is a dense forest that receives enormous amounts of rain throughout the year, at least 80 inches annually (more than six feet!). These forests are packed with life: the trees grow so close together that their tops form a thick canopy overhead, creating a green ceiling that blocks most sunlight from reaching the ground below.

The most famous rainforests are tropical rainforests near the equator, like the Amazon in South America or the Congo Basin in Africa. These hot, wet forests contain an astonishing variety of plants and animals. Scientists estimate that tropical rainforests are home to more than half of all plant and animal species on Earth, even though rainforests cover less than 10% of the planet's surface. A single tree in the Amazon might host hundreds of species of insects, birds, and other creatures.

Temperate rainforests also exist in cooler places like the Pacific Northwest of the United States, where towering evergreen trees thrive in the constant moisture from ocean air.

Rainforests play a crucial role in our planet's health. Their billions of trees absorb carbon dioxide and release oxygen. They also influence weather patterns and water cycles far beyond their boundaries. When you hear about protecting rainforests, it's because losing these forests means losing thousands of species and disrupting systems that affect the entire world.