Augmented Reality is exactly what the name implies: an augmented version of reality created by mixing technology with the known world. It might be a distorted, augmented, or less augmented version of the actual world but in its basic form, augmented reality is a simulation or rather a way of superimposing digital contents into the real context.
http://www.educatorstechnology.com/2013/06/teachers-guide-to-augmented-reality.html