Three short pages, read in order. The decision tree comes first, before any definitions, so you can place your project in a few seconds and see why the question is where pages are composed rather than which technology to use. The second page gives each shape a paragraph and a real case, and explains why several brands or languages are an overlay rather than a fourth shape. The third page lists what the choice does not change, which is most of the platform.
Each shape then has a unit of its own: headless, server-side templating and hybrid, followed by multi-brand and multi-language. The guide ends with a decision table to fill in at a kickoff, the case studies, and what it costs to change your mind later.