One of the biggest IT pro-related announcements Microsoft made this year was about Nano Server, a new small-footprint option for installing Windows Server 2016. Nano Server pushes the concept of a minimal install that Microsoft has offered in previous versions of Windows Server in the form of Server Core.
Unlike Server Core, Nano Server is intended to be a completely headless installation (no local UI and no local console). Also, where the Windows UI can be installed on top of Server Core, Nano Server has no such capability.