Digital elevation model

A digital elevation model (DEM) is a 3-D map of an area's surface. It shows a picture of the land's height and shape, like a mountain range or a hill. The DEM helps us understand the land and water around us. DEMs are made up of tiny squares called grid cells. Each grid cell is filled with a number or a pixel that tells us the height of that part of the landscape. DEMs are like virtual models of the land that help us understand how the land looks and works.