What does the page list (EPUB) primarily provide?

The correct answer highlights that the primary purpose of the page list in an EPUB document is to provide links to static page break locations. This function is essential for users as it allows them to quickly navigate to specific sections or pages within the document. In digital publishing, especially within EPUB formats, maintaining user accessibility and ease of navigation is a key element, and the page list serves this by indicating where breaks occur, thus helping readers to find content efficiently.

The other options suggest different functions that are not the primary purpose of the page list. For example, while summarizing document contents and providing illustrations are valuable for overall usability and comprehension of the material, they do not align with the specific navigation context of the page list. Similarly, while navigation between chapters is important, the page list specifically assists with locating static breaks rather than serving as an overarching navigation tool.