Why use Server Core?

Why am I even talking about Server Core? Hasn't it been around since 2008? Yes, that is exactly why I am talking about it. The Server Core variant of the Windows Server operating system has been around for quite some time, but it seems like many admins are afraid to use it. I work with many different companies from many different industries. Most of them have one big thing in common: they use a lot of Windows Servers, and all of these Windows Servers are running the full GUI (Desktop Experience). Have they heard of Server Core? Sure. Have they tested it out in a lab? Sometimes. Everyone seems to have a slightly different experience level with Core, but it's quite rare to find one in production. Maybe I'm just talking to the wrong people, but I have to assume that there is a majority of us out there, myself included, who need to start using Server Core on a more regular basis.

Why do we need to start using Server Core? Because GUI-less servers are the...