Guix isn't exactly an operating system though, it's a package manager, like apt on Debian. The terminology went through some iterations, but according to the m

Guix isn't exactly an operating system though, it's a package manager, like apt on Debian. The terminology went through some iterations, but according to the manual, Guix can nowadays refer to either: It's a "package management tool for and distribution of the GNU system" (emphasis mine). The distibution can be used standalone (in which case it's called Guix System), or as a package manager on top of a host system.