This Module provides the overall firearms technical context. Lecturers should understand the importance of proper definitions, and why it is important to have a common technical language and classification to fully understand and appreciate the legislative and regulatory framework on firearms, their parts and components and ammunition; lecturers should also be cognizant of why unique identification and registration of arms is important in relation to their tracing and to their role in court as evidence. The technical aspects revealed in this module will help lecturers understand firearms from legal, investigative and judicial points of view. In addition, the nomenclature of a firearm, and the how these elements are just as important as the firearm itself, especially when they are used for illicit actions, like modification, conversion, reactivation or even illicit assembly or manufacturing. Lecturers should also familiarize themselves with the various calibre of ammunition and how a cartridge works and the importance of proper identification of ammunition, especially when performing ballistic identification, tracing or as evidence in court. Having this knowledge acquired in this initial stage will help the lecturers contextualize and understand the synergy this Module has with the rest of the Firearms Teaching Module Series, especially from the licit/illicit, legislative, regulatory and investigative points of view.