- Hyper-V Server can not do anything except Hyper-V and can only be controlled with PowerShell. He has almost no GUI. Virtualname through the GUI can be controlled via a remote snap-in from your computer by using it on the network this Hyper-V Server.
- Windows Server can do everything, including Hyper-V and managed via a full GUI.
Due to the fact that Hyper-V Server can't do anything unnecessary, it has less consumption of resources the OS itself, which means more free resources for virtualos. He put on larger parks hypervisors (the hosting company) to increase the density.
If the prospect of writing comanducci in PowerShell instead of the spear into the interface, and no tasks on the server except Hyper-V suits You, then choose Hyper-V Server.