Source Coordinate System

Maps can be created from data or boundary files in any coordinate system.  The Source Coordinate System is the coordinate system for the original data or boundary file used to create a map layer. A coordinate system normally has a defined projection and datum.  If some map layers are using a different source coordinate system than what you want the map to display, the map layer is converted to the map's Target Coordinate System.  



See Also

Introduction to Map Projections

Target Coordinate System - Map

Assign Coordinate System Dialog