Terrain models are three-dimensional representations of the Earth's surface, showcasing its features like mountains, valleys, and plains. These models can be created using various methods, including physical models made from materials like clay or plastic, and digital models generated through computer software. They help in visualizing and analyzing geographical data. Terrain models are useful in fields such as geography, urban planning, and environmental science. They assist researchers and planners in understanding landforms, assessing natural resources, and predicting the impact of human activities on the landscape. By providing a clear view of terrain, these models enhance decision-making processes.