Vuforia Engine supports the development of various interactive AR and VR experiences through the use of the Rotational and Positional Device Trackers. The Device Tracker provides rotational and/or positional information about where the device is relative to the world. The Rotational Device Tracker is optimal for VR or AR applications that need to leverage 3 degrees-of-freedom. The Positional Device Tracker is great for AR applications that need to put content in the environment or want to provide additional robustness to Target tracking with 6 degrees-of-freedom.
This article describes the use of the Device Tracker in Unity. If you are developing an application for native Android or iOS, see Using the Device Tracker document.