Cartography is the art and science of map making. And maps are 2-dimensional objects for a 3-dimensional world. How can a map accurately show height? It does it through color and contour lines that denote elevation and height. But there are other map objects that can show all of the dimensions of a site.
For instance, look at a map of Mount Fuji in Japan. You see the representation of a mountain. But you can't see how high the mountain really is.
A relief model is a 3-dimensional map. If you look at the 2 views of the relief model of the same area, you see Mount Fuji rising from sea level. You see the snow and ice on its peak. You see how it dominates the landscape. You see the shadows the relief model creates and can imagine the ones at the actual site.
Relief models can make maps come alive.
Photographs courtesy of Peter Allen.