what is Remote Desktop Services in Windows Server 2008 R2 all about?

Seriously, I'm lost in all that sales mumbo-jumbo. Let's say I want 1 or 2 users to be able to remotely log on to a server, run Word, Visual Studio, Firefox, and whatever. Do I gain anything at all if I install Remote Desktop Services? Or do I just install Desktop Experience feature pack, enable remote desktop and voila, nobody will ever notice the difference?

Here's what TechNet says about Remote Desktop Session Host:

A Remote Desktop Session Host (RD Session Host) server is the server that hosts Windows-based programs or the full Windows desktop for Remote Desktop Services clients. Users can connect to an RD Session Host server to run programs, to save files, and to use network resources on that server. Users can access an RD Session Host server by using Remote Desktop Connection or by using RemoteApp.

The good old simple remote desktop can also host a full Windows desktop for remote clients so that they can run programs, save files and do all that stuff. Why do they write about it like it's such a great new invention, besides that they want to sell it? RDSH doesn't seem all that different at all. What do I install when I install RDSH, since all those features are already there in Windows?

What's even more confusing is that you need to take special care when you want to install applications to an RDSH so that they will be usable by many concurrent users. Why? All the modern applications install the program files in one directory, store some common settings in the ProgramData folder and the HKLM hive, and store user specific settings in the Users folder and the HKCU hive. They are designed to be usable by many users on the same machine. 2 or 2000 users can use them concurrently without any efforts. I can sign in with 2 users to a server with only remote desktop enabled, and both of us can run Word or anything without any problems, can't we? So what changes if I set RDSH to install mode, or what happens if I don't? Why is the feature to switch between install and execute mode there at all?

Yes I know of some advantages in Remote Desktop Services, like there's no 2 user limit, it supports virtualization, video acceleration and stuff, it has a whole infrastructure with gateway, web access, connection broker, etc. But I don't need those, so if you take these away, how are these two technologies different? From the articles it seems like they are completely different technologies, whereas it looks to me that they are completely the same at the core, and Remote Desktop Services just adds some additional features, but doesn't reinvent anything.

Solution 1:

You're confusing remote desktop for administration with remote desktop services. Remote desktop for administration is for remotely managing a server via RDP. Remote Desktop Services is for remotely working from a server session as if the remote session were your workstation and running applications within that session via RDP. The conceptual aspects may be blurry but the licensing is certainly perfectly clear. In addition, remote desktop for administration is limited to 2 concurrent sessions and no additional licensing is required. Remote Desktop Services requires RDS CAL's and is limited to the number of RDS CAL's that you've purchased (this isn't a technical limitation, it's a licensing/legal limitation).

They may seem like the same thing and from a technical perspective they are (except for the concurrent session differences) but from a legal and licensing perspective they are two wholly independent things.

If you're running applications on the server while using remote desktop for administration you're most likely in violation of the EULA of both the server and the application.