Augmented reality
Augmented reality is the use of technology to enhance the real world through the use of sensory information (visual, audio, or otherwise) that is added to the actual view of the real world. For example, smart phones have applications that do this, such as Google Sky Map and GeoGoggle. Google Sky Map, for instance, allows you to look at the sky through your smart phone, and will display the names of the stars and other entities that are in the area of the sky that the phone is pointing.
Additional Information
Also see: Virtual reality