TPC can work with Coordinate distances are derived from cartesian coordinates (Northings / Eastings) as opposed to Geodetic distances which are derived from geodetic positions (Latitude / Longitude). When you are doing a typical boundary or topo survey, you are using coordinate distances.
A survey can have one Coordinate Reference System (CRS) that relates it's geodetic and rectangular coordinates. TPC computes coordinate distances by inversing between coordinates on the current CRS and applying the appropriate scale factor (converts between the grid plane and ellipsoid surface) and elevation factor (converts between the ellipsoid surface and the ground elevation). Since the CRS releates the coordinates of a point to its geodetic position, TPC can compute both a coordinate distance and a geodetic distance between any two points.
Area computations are tied directly to the distance type being used. Both traverses and drawings each have a user defined distance type which is used to generate their areas.
The personal edition is not a geodetic edition. It will not include the geodtic distance types, but will include at least some of the coordinate distance types.
Personal, Premium, Professional