Content, Core and Template
The Core supplies Pages, Articles, Categories, menus, media library, languages, permissions, SEO and Layout Engine. The Template presents these data. Content fills editorial spaces and compositions organise display. This separation lets presentation change without moving text into PHP files.
Build an editorial structure
Start with editorial structure: lasting content in Pages, publications in Articles and resources grouped by Category. Then define menus and presentation. Add an Extension when the project needs its own business domain. The official website is itself delivered as a Template and native content.