Marker – an image that is used to identify an Augmented Reality location.  Originally, Markers were images that were printed on a piece of paper and placed strategically for recognition.  Over time, however, object recognition technology allows Markers to be objects, such as automobiles, airplanes, motors and even human faces.

Overlay – the augmentation that is placed virtually over the Marker or Target.  This can be a simple image, 3D object or video, however can also be an interactive object or application.

Target – see Marker