Book excerpt: New technological approaches in dermatologic diagnostics, such as surface microscopy and dermoscopy, are continuously advancing. Anatomical structures can be viewed like never before. Through these new techniques the necessity of a new terminology and a new set of dermoscopic criteria has come up. So far, many different and sometimes confusing terms have been used in designating these microscopic features. However, the daily challenge physicians face when evaluating skin lesions acquires immediate access to the current dermoscopic nomenclature and definition. This unique guide provides a comprehensive, current, and accurate A-Z encyclopaedia to clarify the meaning of surface microscopic and dermoscopic terminology including a broad range of both melanocytic and non-melanocytic skin lesions. It will support dermatologists, histopathologists and all other physicians in charge of a biopsy and excision decision.