A GPS tracking unit, geotracking unit, satellite tracking unit, or simply tracker is a navigation device normally on a vehicle, asset, person or animal that uses satellite navigation to determine its movement and determine its WGS84 UTM geographic position (geotracking) to determine its location. Satellite tracking devices may send special satellite signals that are processed by a receiver.
In this case the GPS tracker is specifically made for cats or small dogs. It is a small unit that is usually attached to a collar and can be used to find the exact location of the cat. This is handy when you can’t find your cat.