drag and droplinuxx-windows
I'm an old-school dinosaur, and I'd like to understand how drag and drop works on the X window system under Linux. Is it build into the X protocol? Is it a function of the window manager? Do applications have to be aware of drag and drop? Is it both the applications and the window manager?
I'm looking for a general technical understanding. If I have specific questions about how to modify an app to support drag and drop, I'll ask them over on Stackoverflow.
An RDP session is not a valid Drag source in Windows (yet?), so copy and paste is the fastest way.
I usually hit ctrl-c and ctrl-v for copy and paste anyway, as personally I find it quicker than drag and drop, plus you don't get stuck waiting for imaginary transfers like when you copy something and then hit right-click to try and paste it between sessions.
Copying and pasting in and out of RDP is slower (transfer time-wise) than copying via a (VPN) share or FTP or HTTP, so I'll usually use one of those for large files, which keeps my cut & paste available for other tasks while it's copying.
this might help you out (I'm Windows 7 but it says it works on Windows 10 as well)!
Download QTTabBar from the following link: http://qttabbar.wikidot.com/
Instructions on how to install and activate are here (plus loads more information): http://qttabbar.wdfiles.com/local--files/documents/install.html
Once you've installed and logged back on (you'll need to log off after installing to let it load up), open up a windows explorer and go to view > toolbars and select QT Base Toolbar.
Now right-click on the bar that has (in my case) Organize, Burn, Work offline and New folder, etc. as shown below: 
Turn on Extra view (left) which will give an extra navigation type view on the left hand side of the explorer window. Setting this window to the desktop with your folders in it, and also setting the main window to desktop as well, you should be able to drag files and hover over a folder. After a few seconds the pop up with sub directories should appear for you to navigate and move your files as needed, another screenshot added below for reference:
There is a lot more to this program but this will hopefully do what you're after!
Hope it helps.
Best Answer
XDnD (wikipedia) is the most widely used protocol, supported by GTK and Qt. It involves both applications and, to a certain extent, the window manager and the program switcher (e.g. GNOME Panel) if one is running.