This is how it works Desktop GIS represents the real world on a computer similar to the way maps represent the world on paper. But desktop GIS has power and flexibility that paper maps lack. To help you understand how desktop GIS works, we'll break it down into the conceptual pieces, and take them one piece at a time. We'll start with basic ideas, like how maps convey information about places and how scale influences the size of what appears on the map. Then we'll advance to the principles governing how a desktop GIS works, like how it stores and links information and where it gets its power and flexibility.
Maps are graphic representations of the real world.
Since the real world is infinitely more detailed than a map can be, we say that maps give us a generalized view of the real world. Natural objects, such as mountains, rivers, and valleys as well as man-made objects such as cities, roads, and buildings can all be represented on maps. The objects represented on maps, whether natural or man-made, are called map features, or simply features . The features representing downtown Portland are shown on this map. Each map feature has a location, a representative shape, and a symbol that represents one or more of its characteristics.