The others have provided the link - I'll add it's the activation/licenses are the part you really pay to get but you can do that after install (or not at all, i

The others have provided the link - I'll add it's the activation/licenses are the part you really pay to get but you can do that after install (or not at all, it's just nagware outside of some personalization settings). Windows Server 2019 is going to have some wonky defaults and components out of the box. Some apps will report not being compatible but it's not usually a problem. That said, Windows Server 2019 is neither the oldest or newest version of Windows Server based on the Windows 10 codebase so I'm not sure why you'd bother with it in particular.