It's kind of like a hierarchy of increasingly narrowing scope.
Super User Stack Exchange is the widest: includes questions for all computers and operating systems, including hardware and software (but not software development!—go to Stack Overflow for that!). See: https://superuser.com/help/on-topic:
Super User is for computer enthusiasts and power users. If you have a question about …
- computer hardware,
- computer software, or
- personal and home computer networking
and it is not about …
- programming and software development,
- video games or consoles,
- websites or web services like Facebook, Twitter, and WordPress,
- electronic devices, media players, cell phones or smart phones, except insofar as they interface with your computer,
- issues specific to corporate IT support and networks,
- asking for a product, service or learning material recommendation,
… then you’re in the right place to ask your question!
Next is Unix & Linux Stack Exchange. It is more narrow, requiring that the operating system be Linux, FreeBSD, Unix, or Unix-like. This includes macOS it sounds like, but if your question only applies to Macs, use Ask Different at https://apple.stackexchange.com/ instead. For Unix & Linux Stack Exchange, see: https://unix.stackexchange.com/help/on-topic:
Unix and Linux Stack Exchange is for users of Linux, FreeBSD and other Un*x-like operating systems.
If your question is about:
- Using or administering a *nix desktop or server
- The Unix foundation underlying OS X (but generally not frontend application questions)
- The underlying *nix OS on an embedded system or handheld device (e.g. an Android phone)
- Shell scripting
- Applications packaged in *nix distributions (note: being cross-platform does not disqualify)
- UNIX C API and System Interfaces ( within reason )
then you're in the right place. Note that Ubuntu posts are a special case. If your question applies to Ubuntu only, or you're looking for answers that are Ubuntu-specific, you should post it on the Ask Ubuntu Stack Exchange site. If your question applies to other distros or you welcome more generic solutions, you're in the right place here.
Finally, comes the Ask Ubuntu Stack Exchange. It is the narrowest scope. If a question is for Ubuntu only, don't ask it on Unix & Linux Stack Exchange, ask it here. See: https://askubuntu.com/help/on-topic:
Ask Ubuntu
It's a questions and answers site for Ubuntu-related questions. It's also a place to share knowledge about Ubuntu.
Note that there is a lot of overlap in where you can ask questions. Use your best judgment. If in doubt, and you're using Ubuntu, just ask there on AskUbuntu. It's probably safe.
If I'm having a problem with Linux Mint, which seems likely to be the same in Ubuntu, is it appropriate to post it on Ask Ubuntu?
Since Mint is so close to Ubuntu, you can probably ask on Ask Ubuntu (Stack Exchange site) for Mint too and be just fine. But, technically, since it's not Ubuntu, the guidance above says you should ask on the Unix & Linux Stack Exchange instead. See here for all recent questions on there tagged with linux-mint
, which is exactly the tag you should use when asking there: https://unix.stackexchange.com/questions/tagged/linux-mint. With 3682 questions there with that tag (as of 12 Mar. 2021), it looks like that's the right place to ask.
Why so many sites? From my comment below, I think:
@pavel_orekhov, I think there is merit in creating multiples for one reason & one reason only: ownership. In a communist Stack Exchange, there is one site & all users must use it equally. But since they have no control over it they get disenfranchised & leave [or disengage]. In a free society with ownership, subgroups which are otherwise part of a larger group can break off & create their own community of more-narrowly-focused content. They feel ownership. This ownership gives them a sense of belonging, purpose, & meaning. It keeps them engaged. Their site thrives. Ownership is key to all things in life.