I have been looking and I have not found a definitive answer to this question.
HyperV may be installed in 3 different manners
1) HyperV Core, no GUI, no license
2) HyperV Server with GUI (full server 2012 install, requires license)
3) HyperV Core, minimal install (have to install GUI version and then "back off" GUI
Now I am told that there is a version called Hypervisor, free, no license. Named Hyper-V Server 2012. Is this the same as core? I installed core and there is no GUI. You have to run Sconfig to make changes to Server Core.