Hi all - I am learning about Linux and want to see if my understanding is correct on this - the list of major parts of any distro:

1. the Linux Kernel
2. GRUB or another bootloader
3. one or more file systems (gotta work with files somehow, right?)
4. one or more Shells (the terminal - bash, zsh, etc...)
5. a Desktop Environment (the GUI, if included, like KDE or Gnome - does this include X11 or Wayland or are those separate from the DE?)
6. a bunch of Default applications and daemons (is this where systemd fits int? I know about the GNU tools, SAMBA, CUPS, etc...)
7. a Package Manager (apt, pacman, etc...)

Am I forgetting anything at this 50,000 foot level? I know there are lots of other things we can add, but what are the most important things that ALL Linux distributions include?

Thanks!