Rainforests are called rainforests because of the high amount of rainfall they receive.

Here's a breakdown:

* "Rain": This part of the name directly refers to the abundant precipitation that characterizes these ecosystems.

* "Forest": This part indicates the presence of a dense, lush forest filled with diverse plant life.

Rainforests typically receive at least 80 inches (200 cm) of rain annually and some areas receive even more. This constant moisture is the key factor that enables the unique and rich biodiversity found in rainforests.