Sections are helpful in making large documents more manageable. You can gather all the information on one topic into a section. Sections collapse into one-line paragraphs or expand to display all the text in the section, so a reader doesn't have to read sections that aren't of any interest. Figure 16.6 shows a document with collapsed sections.
When you gather text into a section, a small triangle appears to the left of the section head. To expand a section, click this triangle (called a twistee). Clicking again on the twistee collapses the section. To expand all the sections in a document, choose View, Expand All Sections from the menu. To collapse all sections, choose View, Collapse All Sections from the menu. Figure 16.7