Mountainous terrain refers to areas characterized by significant elevation changes, including hills, peaks, and valleys. These regions often feature steep slopes and rugged landscapes, making them distinct from flat or gently rolling areas. Mountains can be formed through geological processes such as tectonic activity, erosion, and volcanic activity. The climate in mountainous terrain can vary greatly with altitude, leading to diverse ecosystems. Higher elevations typically experience cooler temperatures and different vegetation compared to lower areas. This variation supports unique wildlife and plant species, contributing to the ecological richness of places like the Rocky Mountains or the Himalayas.