  Augmented Reality (AR) is used for various applications associated with the
real world. In this paper, first, describe characteristics and essential
services of AR. Brief history on Virtual Reality (VR) and AR is also mentioned
in the introductory section. Then, AR Technologies along with its workflow is
depicted, which includes the complete AR Process consisting of the stages of
Image Acquisition, Feature Extraction, Feature Matching, Geometric
Verification, and Associated Information Retrieval. Feature extraction is the
essence of AR hence its details are furnished in the paper.
