Upgrading your solution also keeps it running smoothly with the latest technology and infrastructure advances, so you can maximize your existing investment in other Microsoft products and services.
Select your current release below to see key examples of how Microsoft Dynamics NAV 2015 has become even faster to implement, simpler to use and with the power to support your business ambitions. Cloud or on-premises deployments give you the flexibility to choose what’s best for your business. You'll also be able to see which of the licensing options give you access to these new features and capabilities.
LINK :- http://www.microsoft.com/dynamics/upgrade-compare/nav/default.html