Cinnamon uses the muffin window manager (wm). Window managers are the things which decide how your windows are laid out. When you open a Firefox window for example, it decides which workspace it will open on, how large it will be, if it will be full screen, if it’s gonna only be on the right side of the screen, etc.

Here’s what xorg and wayland are. Some bars are meant for specific window managers, and some work for all xorg window managers or all wayland window managers. So what you’re using is important when suggesting a bar.