Navision is the name of software originally developed by the Danish company PC&C in 1987.
In 2002 the company was sold to Microsoft. But read the full history of Navision here.
For a short while after the release of Navision 3.01 aka Navision Attain, Axapta was also called Navision Axapta.
In 2006 Microsoft changed the name of Navision to Microsoft Dynamics NAV.
The latest version of Navision is Microsoft Dynamics NAV 2016 released in October 2015.