Mountain building, also known as orogeny, is the geological process by which mountains are formed. It occurs when tectonic plates collide or converge, causing the Earth's crust to be pushed upwards and folded, resulting in the formation of mountain ranges. This process can involve a variety of geological activities such as faulting, folding, and volcanic activity. Mountain building plays a crucial role in shaping the Earth's surface and has significant impacts on the environment, climate, and biodiversity of a region. Studies in this area help to understand the geologic history and formation of mountains, as well as their current dynamics and future evolution.