Map Coordinate System
The Map Coordinate System is the system of coordinates associated with the current map projection in the map window. The units are those associated with the projection, for example, if the map is in geographic projection the coordinates are in degrees, if it is in UTM or BC Albers projections the coordinates are in metres.
The cursor location coordinates may be turned off and on or switched between Map Coordinate System and Lat & Long values by going to the Pop-up Menu > About > Preferences and picking the preferred system.