It is perfectly possible to write whole documents using nothing but section headings and paragraphs. As mentioned in § 2.6, novels, for example, usually consist just of chapters divided into paragraphs. However, it’s more common to need other features as well, especially if the document is technical in nature or complex in structure.
In Chapter 2 ‘Basic structures’ we saw how to create a hierarchical document structure with chapters and sections and paragraphs; this chapter covers the other building-blocks which you need within your structure: lists, tables, figures (including images), boxes like sidebars and panels, block quotations, and verbatim text (computer program listings). In Chapter 5 ‘Textual tools’ we will cover the textual tools that you need inside text: footnotes, marginal notes, cross-references, citations, indexes, and glossaries.