- Many WWW Servers have a hierarchical structure, making it easy
to traverse them.
- Many servers contain complex non-hierarchical structures, and documents
available through "clickable images" and fill-out forms.
Such servers are difficult to traverse.
- Links may point to documents on other servers, but not necessarily
to the root of those servers' hierarchy.
- There are no menus: links to documents are embedded in other documents,
so in order to find all the documents one must "read" all the documents.
With Ftp and Gopher servers it is easy to retrieve just partial
information by only loading directories or menus, and not the actual
documents. With World Wide Web the documents are the menus,
so it is not possible to retrieve partial information.