When Microsoft introduced the Operating System as a Service with Windows 10, a lot of people got started getting confused because of the different version numbers and build numbers, all the while Microsoft was telling us it was really the same operating system. Okay, I think we have it clear now… three years later.
So just to make things fun, Windows Server 2016 is offered as an OS as a Service as well… although mercifully we do not have to update our servers nearly as often to stay current.
It is one thing to mess around with our desktops. Messing around with our servers could be disastrous on an entirely different level. So, unlike Windows 10, monthly updates (or Cumulative Updates, if you are just catching up) will not change the version of the OS. If you installed a Windows Server from the original release (Version 1607), it will remain Version 1607. The only thing that will change is the OS Build.
Notice the different build… the original reads OS Build 14393.1884, and after applying Cumulative Update for Windows Server 2016 for x64-based Systems (KB4093119) it kicks up to OS Build 14393.2189.
Some of us in the know feel that calling every release of Windows 10 the same operating system is like saying that a 2013 Ford Mustang is the same as a 2018 Ford Mustang; just because they have the same name does not make them the same car. Similarly, Windows 10 Version 1607 is hardly the same as Windows 10 Version 1803. They look the same for day-to-day operations, but under the hood there are real differences (i.e.: look for your Control Panel in the Windows Menu in 1803).
The team at Microsoft understood that you cannot just upgrade versions with servers. There are too many things that could go wrong. As such, Windows Server 2019 is currently in pre-release testing (we used to call it beta testing… I can’t keep up with the current names). When the time is right, you can upgrade.
In the meantime, should you be upgrading all of your servers that are Version 1607 to Version 1803? In general I wouldn’t, but there may be use cases where you would want to.
I hope this clears some things up for you!