Linux

Okay, so the Linux ecosystem is more modular than Windows. Windows is synonymous with its Graphical User Interface (GUI) for reasons I'll get into later.

With Linux, there are several GUIs available to choose from. These tend to fall into two main categories: Tiling Window Managers, and Desktop Environments.

Tiling Window Managers have minimal on-screen UI elements, usually they're meant to be used with keyboard combos with little usage of the mouse. A major feature is everything that is running is visible on the screen, when you open a new window, another window divides in half to give it room, "tiling" the screen. Some examples of TWMs include i3 and Awesome.

Desktop Environments are going to be more familiar to newcomers from Windows or MacOS. They're made more for mouse control, several have what you would recognize as a taskbar, start menu and system tray. Windows can be stacked on top of each other like papers on a desktop, exactly like MS Windows does. Some more closely resemble MacOS though none behave exactly the same way. Some examples of DEs include Gnome, KDE, MATE, and Cinnamon.

Cinnamon is a DE made by the Linux Mint development community, and the default/flagship DE for Linux Mint. It is designed to be familiar and easy to use for Windows users. KDE's Plasma DE is similar in many ways to Mint although it's based on different tech; KDE is based on qt, Cinnamon is a distant fork of Gnome and based on GTK. Some are designed to be more minimal so they take up less system resources, like xfce and LXDE, others are trying mostly to resemble MacOS, like ElementaryOS' Pantheon DE. Then there's Gnome, which I goddamn hate.

For a beginner, the choice of DE is going to present most of the differences you'll notice when trying out distros. It can be instructive to try, say, Kubuntu and Fedora KDE. Both ship with the KDE Plasma desktop, but the underlying OSes are different. Then try out, say, Fedora Workstation (with the Gnome desktop) and Fedora KDE. That exercise will give you a good understanding of distro vs DE.

Edit to add: It's kind of like launchers on Android. You can go in the Google Play store and install a different launcher on your phone, you can make a Samsung Galaxy look like a Google Pixel. Linux DEs work the same way, you can install KDE or Cinnamon the same way you'd install a normal app, you can have multiple and switch between them. It's not a great idea but you can.

The desktop environment is all the stuff like the taskbar, the settings menus, the application launcher, the login screen, that kind of thing. It’s the system level user interface.

You choose which one by which distro you download. Linux mint uses cinnamon, Ubuntu and fedora use gnome. There are “flavors” of Ubuntu and fedora that use KDE. That’s why I suggested ventoy: you can download a few different ones and boot into them without making a new thumb drive.

If you don’t feel like bothering with any of that, just use Linux mint. It’s good.

If a computer is a car, then Linux(the Kernal) is the chassis. Mint (the distro) is the motor, and Cinnamon (the desktop environment) is the fancy interior.

KDE plasma is a fancy interior that works with tons of different motors.

Cinnamon is designed for mint and works best with it.

DISCLAIMER: All of this is analogy and isn't technically correct in a pedantic sense, but it works well enough for me. I'm sorry if my analogy isn't exactly accurate.