Understanding
coordinate systems
There are
two types of coordinate systems: geographic and projected. A geographic
coordinate system is used to locate objects on the curved surface of the earth.
A projected coordinate system is used to locate objects on a flat surface—a
paper map or a digital map displayed on a flat computer screen.
Each of
these coordinate systems attempts to model the earth and feature locations
accurately, but, as you will learn, no system is completely accurate. In this
topic, you will learn the basics of how geographic and projected coordinate
systems work.