Final answer:
The Table of Contents acts as a navigational tool in digital textbooks, showing chapters and subsections for easy access.
Step-by-step explanation:
The Table of Contents serves as the road map or table of contents for active files, facilitating quick navigation and organization in digital textbooks, especially on platforms like LibreTexts. When viewing longer pages, the Table of Contents is quite useful for swiftly accessing different sections and subsections, reducing the need for scrolling. On a computer, it is displayed in the upper right corner of the page, and on a mobile device, it appears at the top of each page. Additionally, navigational aids such as 'breadcrumbs,' blue arrows for virtual page turning, and hyperlinks within the text contribute to the ease of navigation through the contents. The Table of Contents' functionality includes expanding or collapsing subsections using plus or minus signs and jumping to specific points within the text.