Menus and collections
Choose navigation or an ordered group of content.
A menu is a navigation tree. Its entries can have children, allowing submenus. The website's design chooses which menu to display and where.
A collection groups resources through Has part connections. It can represent a guide, series, or other ordered set. A collection can contain another collection when the site supports that structure.
Both reuse existing pages. Neither duplicates their text or automatically publishes them. A page can appear in several collections and menus.
Use a menu when the goal is navigation. Use a collection when the goal is to present related content as a set. The website may display collection navigation too, but that is a design choice.