Guys, you are starting to sound like MS users.
Linux is the kernel. The major tools that run over the shell of the kernel are a majority from GNU/FSF.
Distributions can use all, some, or other variants of this. But the kernel is usually the linux kernel (herd is about, but not yet ready after 20 odd years).
Now, on top of all that you have window managers, or desktop environments. The former being something like fluxbox or blackbox and the latter being something like Gnome or KDE. For embedded systems somethong like (or based on) busybox is used.
I sometimes use xfce4 DE, but now use DWM WM 99% of the time ( see http://dwm.suckless.org/
But whatever, it is still a GNU/Linux system, no matter how you say it.
Edited by Lethe (Tue 18-Oct-16 20:46:45)