What is Nano Server ?
Nano Server is a new installation option that became available with the arrival of Windows Server 2016 Technical Preview. It is a purpose-built, stripped down operating system designed to run services and to be managed remotely.
Windows Server 2016 will offer the following installation options:
Nano Server has been designed according to Zero-Footprint model and its size on disk is around 500MB. It has no GUI, binaries or metadata in the OS image, it sets up significantly faster and requires far fewer updates and restarts than Windows Server.