As a hyper simplistic explanation :
Window Managers (WMs) are essentially keyboard centric highly stripped down and highly customizable Desktop Environments in a way. This isn't completely correct, but for the sake of simplicity it'll do.
I can give you a much more technical explanation if you want.
I'm not in the mood to read something super technical right now- But actually y'know what, I will be tomorrow. Hit me with that shit or if it's as much as you seem to be implying, make a post and link me in.
A Window Manager is a type of compositor or X client (depending on if it's based on Wayland or Xorg respectively) that manages the placement and appearance of windows on the screen.
It is responsible for the appearance and behavior of windows, determining the border, title bar, size, and ability to resize windows, and often providing other functionality such as reserved areas for sticking dock-apps or the ability to tab windows.
It can be part of a Desktop Environment(DE) or be used standalone.
Often times when WMs are referenced it's in reference to standalone WMs which are often keyboard centric and come in various different forms. For example tabbed, tiling, dynamic, stacking, dynamic tiling, etc.
Some popular Xorg based WM in Linux include i3, BSPWM, DWM, Awesome, Fluxbox, Openbox, WMii, Xmonad, etc.
Some popular Wayland based WM including Sway, Hyprland, River, DWL, NeWM, etc.
Then there's WMs built-in to Desktop Environments like Kwin(KDE Plasma) and Mutter(Gnome).
If you're interested there's an Arch Wiki with even more info.
I'mma come back to this, but for now, I'm definitely ready to make the switch to linux. Fuck microsoft.
I've used ubuntu in the past on and off back in high school, but it never really stuck. Didn't get the point, couldn't play games, disk space overhead that I could use for ut2004 instead, that kinda thing. Now I get the point and I almost don't play games anymore (though I hear linux is much a more mature gaming system now, figures) and I'd like to try again, but I doubt the least common denominator ubuntu is the right choice. Which instances/communities are going to be the best for a beginner? I'm going to need help with a lot of stuff, I remember trying to install network drivers was a pain in my ass, using the command line and remembering commands and operators and that sort of thing, the filesystem and filetypes were unfamiliar and confusing for that reason, just a lot of things. Where do I start?
A window manager, and you are usually using one and can't "stay away" from it, that person just doesn't know what they're blabbering. What they are trying to say is that choosing a window manager may lead you to trying some unusual workflow.