While maps, place names, and landmarks are important for young children to learn, geography as a science is far more about how geographic entities and the relationships they have to each other effect the world. Those entities can be real and physical. Examples of a real geographic entity might include a river, a building, a tree, or a road. Other entities can be present on a map, but invisible to the human eye. An entity that is invisible to the human eye could be a border around a city, change in the health of vegetation mapped using infrared imaging, a group of people, or a map of the potential spread of a wildfire or other phenomena.