EasyAR target is flexible, you can read more from EasyAR Target Configuration. A target represents one object that can be tracked by a tracker. For ImageTracker and ObjectTracker, the target can only be tracked after loading into a tracker. You can create many trackers in EasyAR, as many as you wish. When an target is loaded into a tracker, it will be tracked by that tracker and other trackers will not touch it. So when you load a target into a tracker, the load into another tracker will fail unless you unload it from the previous tracker first, one expection is that the Unity Behaviour interface will do the unload automatically.