Locating - minsan lang, Tracking - continouos update of the location, sinusundan.
I have no experience with the network service for locating or tracking by using the cell site to know which particular AREA the phone is connected. What I built was a GPS tracker with a GSP module from parallax connected a GSM modem. Kaya kapag nagtext ka ng "Wer na U?", magrereply xa ng "Her na me" with the latitute and longitute of the location. By plotting the coordinates in an electronic map (nasa PC), malalaman kung saan ang exact location, witin 10 meters accuracy.
Kaya kapag naka track si Misis kay Mister, at sabi ni Mister na nasa Cubao daw xa, alam ni Misis kung nasa Ali Mall o di kaya nasa Ali bangbang. Marami ding mga matronang nagrerequest kung may injectable version nito.
Anyway, I hope this spells the difference between locator and tracker.