One must differentiate between updating a system and upgrading a system. In general, most of the NAV development work we will do is modify individual NAV systems to provide tailored functions for end-user firms. Some of those modifications will be created by developers as part of an initial system configuration and implementation before the NAV system is in production use. Other such modifications will be targeted at a system that is in day-to-day production to bring the system up to date with changes in business process or external requirements. We'll refer to these system changes as Updating.

Upgrading is when we implement a new version of the base C/AL application code distributed by Microsoft and port all the previously existing modifications into that new version. First, we'll discuss Updating, and then we'll discuss Upgrading.