New concepts
Page landmarks, thematic sections, independent articles, complementary asides, scoped headers and footers, figures with captions, logical headings, labelled navigation, meaningful image alt text, and public-page document metadata.
What changed?
Chapter 1 groups content mainly with divs. This chapter chooses elements that communicate what each region means while the pages still have no CSS.
Lessons
Checkpoint
Outline a page with one main region, labelled navigation, at least one headed section, one independent article, complementary content, and a page footer. Explain why each element fits its content.