That is not a spectrum of open source. They are all open source, as in you can access the source code without restriction. These licenses just limit what you can do with the source code.
Low end: “you can see the source but can’t do anything with it” (questionable whether this counts as open source at all)
High end “do what you want, it’s literally yours” (public domain).
One can debate where the low boundary of “open source” is, or what makes one license more or less free than another, but the spectrum is the range of limitations.
That is not a spectrum of open source. They are all open source, as in you can access the source code without restriction. These licenses just limit what you can do with the source code.
Well, yeah. That’s what the spectrum is.
Low end: “you can see the source but can’t do anything with it” (questionable whether this counts as open source at all)
High end “do what you want, it’s literally yours” (public domain).
One can debate where the low boundary of “open source” is, or what makes one license more or less free than another, but the spectrum is the range of limitations.