On paper, it is easy to tell where a work begins and ends. We can pick up a book and know it to be a unified, bounded object. That same work in an electronic hypertext environment may lose much of its coherence. The text becomes decentred; it is harder to determine where the book's boundaries are. Nevertheless, for the sake of convenience, we will continue to use the term "book" (or "hyperbook") to refer to a grouping of electronic text which can be considered as an entity.
This is distinct from the term "hypertext," which refers to the defining form of the work as a structure. An electronic book with hypertext features is a hyperbook. This distinction is not usually made in the literature; the two concepts being elided into one. We believe this lack of precision leads to sloppy arguments, though we acknowledge that it is sometimes desirable to use "hypertext" in a more general sense.