Metallography is the study of the structure of materials, i.e. metals, ceramics, polymers, and composites. Specimens are prepared to be viewed either by the light optical microscope (LOM) or the scanning electron microscope (SEM). Photography (B&W and color, and/or "analog" and digital) is used to document the structures. The analysis of the structure is used to correlate various engineering properties to solve problems in fabrication, processing, or failure analysis...that's it in a nut-shell...thanks for asking...!!!