@saltman ,
Instructure put an audience label on everything as a way to help direct people, but they are not restrictive and you are free to attend any session, no matter what the labeled audience might be. The reason it was labeled Higher Education is probably from a form that they had us fill out when we made a proposal -- there was no choice for "General" or "Everybody".
For example, my presentation is suitable for any Canvas user (students won't benefit much), but since I teacher higher education, I put that down as the track and that's how it got labeled. I know of other people who did the same thing.
The core functionality of Canvas is the same, but there are some features that might not be enabled for your institution and I believe there is a feature called "K-12". So most of Canvas is the same, but there are a few things that aren't enabled for everyone.