A GPS tracking unit, geotracking unit, or simply tracker is a navigation device normally on a vehicle, asset, person or animal that uses the Global Positioning System (GPS) to determine its movement and determine its WGS84 [1] UTM geographic position (geotracking) to determine its location.

Locations are stored in the tracking unit or transmitted to an Internet-connected device using the cellular network (GSM/GPRS/CDMA/LTE or SMS), radio, or satellite modem embedded in the unit or WiFim work worldwide.

Various companies buy position and track data for marketing. Also used for military and criminal, to shut down and pick up repossession/thefts and find truck loads. Tracks can be map displayed in real time, with GPS tracking software. smartphones with GPS capability.[2]

GPS antenna size limits tracker size, ofter smaller than a half-dollar. In 2020 tracking is a $2 billion business plus military-in the gulf war 10% or more targets used trackers. Virtually every cellphone tracks its movements and per most cell user agreements uploads the track data, creating trillions of sellable locations and tracks, value varies from fractions of a mil to dollars per point and user association.