The defense industry covers a gamut of products and services related to military service. Products of the defense industry are most identifiable to the public, such as military vehicles, guided ordnance, electronic detection, communications and encryption. While not as recognizable as many of the defense-related products, but just as great in importance, are the services of defense contractors. Typical services in the defense industry include technicians to support advanced military technologies in the field, construction labor and logistical personnel such as mechanics, truck drivers, and caterers.
Like a Venn diagram, many other industries overlap to form the defense market. Much of the aerospace field is devoted to military aviation and missile technology, while heavy industry is largely responsible for the manufacture of armored vehicles and heavy weapons such as artillery. The field of armaments falls mostly inside the defense sector, but because of crossover with the civilian markets and their simplified operation and manufacture, are treated as a separate industry.