Up to a few years ago, I had been dealing with this since Citrix came out with the original WinFrame (Windows NT terminal server 3.51).
If you are running Windows in a work environment (not just goofing around in a home lab) you really need to worry about being properly licensed with desktop/terminal Client Access Licenses (CALs). And they are real dicks about wanting licenses for everyone who CAN access the software even if they never will.
Don’t think, “Who will know.” All it takes is a report from one disgruntled employee to get the software “police” in for an audit.
So, if you have 10 people using remote desktop to a windows box, you’ll need to get a version of Server that has Remote Desktop Services (aka Terminal Services) and 10 RDS CALs. You might need regular file server CALs as well depending on your use-case.
It adds up pretty quick, won’t save you any money, and often isn’t worth the trouble unless you are running some very expensive, specialized software package on the server that requires a dongle or something.
Having said that, setting up a beefy Linux server and using thin clients to give a bunch of worker-bees access to a MATE desktop with LibreOffice can work well. Or a bunch of Chromeboxes and G Suite (google apps) can be cheap too.