Coordinate Types
This setting controls from which location or point of view you are looking at the sky from when you display charts or the higher accuracy planet positions displayed on the Statistics tab. Geocentric coordinates are the planets positions as they would appear in the sky if you were looking out from the earth's core. Topocentric coordinates make corrections based upon the location you are actually viewing from.
The difference is small for all planets except the Moon which can differ by almost 1 degree. This is only important when considering which type of lunar return you wish to do as the difference of 1 degree is about 2 hours of lunar motion which is equal to one sign rising on the ascendant.