Hierarchical Document
A hierarchical document is a structured set of pages pertaining to a particular area
or subject. It can be a part of a virtual library.
The document's hierarchical structure can be viewed either as an
outline consisting of pages or as a tree where its nodes represent pages of the document.
Links built into these hypertext documents facilitate the navigation
among the pages. Navigation consists of the upward, downward, and across movement in the
hierarchical structure as well as the movement from one document to
another.
Figure 1. Two views of the document structure using navigational tools.