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:
- the Linux Kernel
- GRUB or another bootloader
- one or more file systems (gotta work with files somehow, right?)
- one or more Shells (the terminal - bash, zsh, etc…)
- a Desktop Environment (the GUI, if included, like KDE or Gnome - does this include X11 or Wayland or are those separate from the DE?)
- a bunch of Default applications and daemons (is this where systemd fits int? I know about the GNU tools, SAMBA, CUPS, etc…)
- 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!
I don’t know how helpful it is to split stuff out like that. Especially grouping so many things under “default applications and daemons”, which is most of what a desktop distro is. Also depends largely on a PC vs server setup.
should list an init system as its own bullet, which others have mentioned.
“one or more shells” doesn’t mean that much. Yes, every distro includes one but the only difference between a terminal and any other application is that a terminal needs to be able to escalate to root privileges. You can think of it as just another default (but special) application. A lot of stuff that people think about when they think of Linux distros is just various clever mechanisms for supporting the terminal shell. Like the PATH environment variable. If you are using actual desktop applications other than a terminal, there isn’t any interaction with the terminal shell application.
There’s also fwupd, for updating firmware (your hardware is gonna be running out of date/buggy/insecure code if you don’t have this).
The dbus daemon falls under the “daemons” bullet but it’s pretty important, like wayland/x11 it’s another IPC mechanism you need for programs to work correctly.
There’s also the sound system. PipeWire is the modern one that implements the interfaces of various other sound systems so existing applications work with it. https://pipewire.org/ (PipeWire also has its own IPC protocol like dbus/wayland/x11).
flatpak, snap, distrobox, toolbox, docker, podman, etc. for running sandboxed PC/server applications. I assume there are some programs that are flatpak-only these days.
gsettings/dconf for Windows-registry like config that many programs use.
There’s also plugging in an implementation of the glibc Name Service Switch, which allows libc to use a mechanism other than /etc/passwd and related files for user accounts, internet service names, DNS resolution, etc. . systemd can provide NSS implementations using its own user account mechanism.