Set Coordinate System (Geospatial Modeling Wizard)

If there is no projection (.prj) file with the map or you define two fields from a data source as a set of coordinates, you must set the coordinate system.

Default geographic (longitude and latitude)
The coordinate system is longitude and latitude.
Simple Cartesian (X and Y)
The coordinate system is simple X and Y coordinates.
Use a Well Known ID (WKID)
"Well known ID" for common projections.
Use a Coordinate System Name
The coordinate system is based on the named projection. The name is enclosed in parentheses.