Fundamental Concepts Related to a Plane Mirror

Had the fundamental nature of mirror been discovered earlier, many of its different concepts could have been used for better understanding of crystallographic problems. However, since it has already been discovered now and some crystallographic confusions/ambiguities have already been explained/resolved successfully using the concept ‘mirror combination scheme’, it is obligatory to review the fundamental concepts related to mirror in somewhat details not only just to refresh our knowledge but they also turn out to be quite useful for understanding the crystallography related problems in different ways and will be clear in other chapters.