Navision is multilanguage enabled. This means that a localized version of Navision can present itself in different languages. It is possible for the user to change the language that is used to display texts, and the change is immediate. There is no need to stop and restart Navision.
You should not confuse the multilanguage capability with localized versions. A localized version of Navision is a version of Navision that has been adapted to a local market. This means that all texts that are presented to the user have been translated into the local language, but it also means that functional areas have been adapted to the requirements of the local market.
A multilanguage version of Navision is a localized version of Navision that you can run in different languages while all other local adaptations remain the same. For example, you can run the Swiss version of Navision in German, French and Italian, but it is still a Swiss version of Navision in all other aspects. It is not the same as, say, a French version of Navision.
You should also be aware of the distinction between changing the language of Navision and changing the language of the data stored in Navision. You can address the first issue by enabling the multilanguage features. These features make it possible for the user to change the language of all the texts displayed by the application in captions for text boxes, on command buttons, in menus, and so on.
Changing the texts that are stored as application data is not part of the multilanguage capability. This is an application design issue. Examples of such texts are the names of items in the inventory or the comments for a customer. In other words, these types of text are not translated.