[gdavisson]

Ignoring the legal and accounting details, the basic idea is that macOS is something that Apple includes with each Mac computer that they sell.

If you don't own a Mac, you don't own macOS. If you own a Mac and some other computer(s), you own macOS for the Mac, but not for the computer(s). You might've purchased an upgrade to a newer version of macOS, but if you don't already own a Mac, you don't have something to upgrade, so the upgrade doesn't grant you ownership of macOS.

Now, from a legal point of view, it's a good deal different from (and more complicated than) that, but that's the basic idea. So don't make the mistake of thinking that because Apple gives macOS away for free to Mac owners, and don't use elaborate and onerous copy protection or license-tracking nonsense, that you're entitled to install it on something other than a Mac.