Biomechanical preparation is the most important step of root canal treatment. Files are an integral part of this step. Over the years, there have been many advancements in the field of Endodontics, one of the major being the introduction of Rotary files. Continuous evolving metallurgy and file designs have made Endodontics more patient as well as dentist friendly. A dentist should be well versed with all the file systems in order to provide efficient Endodontic treatment. This book provides a comprehensive review of the basic file systems, their design and advancements over the time.