Hi, I would like to know when to use X,Y -cartesian coordinate system and when to use LAT/Longs. I want to use it for address reverse geocoding.

[Ravi_Nigudkar]

I am trying to accurately use LAT /LONG data instead of X,Y data for obtaining addresses.

I want to know what is more accurate x, Y coordinates or the LAT/LONG values.

[ShanaBritt]

Are you getting different results depending on if you use geographic lat/long or projected coordinates as input for reverse geocoding? Are you using the ArcGIS World Geocoding Service to perform reverse geocoding?