Hi Paul,
it doesn't have to vary. I'd say a project where different page types are built by different teams and where these pages are only connected via links would quality as a micro frontends architecture.
My books starts with exactly this example [1].
However, for many use-cases this very simple approach will not be sufficient. You might want to show functionality from different systems on the same view. To enable this we need a
composition technique. The most basic one is to use an iframe, but you can also use solutions like AJAX, Server-Side Includes or Web Components to provide a more performant and seamless user experience.
If your use-case requires client-side rendered
page transitions for an app-like user experience you might want to move from links (hard navigations) to an overarching client-side router (aka application shell) that enables soft navigations. Then you're building a Single Page App that consists of Single Page App. I'll address all of these topics in the main part of the book.
I've also set up a little site, The Tractor Store[2], where you can see the running example code from the book. Example #1 is "Links & Pages"
\ Michael
[1]
https://livebook.manning.com/book/micro-frontends-in-action/chapter-2
[2]
https://the-tractor.store