Dense forests in which plenty of rain falls all year are called rainforests.

More specifically, they can be called:

* Tropical rainforests: These are found near the equator and have high temperatures and humidity year-round.

* Temperate rainforests: These are found in cooler climates and have a rainy season, usually during the winter months.

Both types are characterized by tall trees, lush vegetation, and a high biodiversity.