Start with One table, four types: pages, books, units and book pages are one table underneath, so most of what you learn about one applies to all, and the page ends with the five content types side by side. The next four pages take one type each, with its routes, its template variables and the code to render it: the page tree, books, blogs and FAQ. Which type, or none closes the unit with three worked decisions and the test that sends content to a custom entity instead.