The structure of hypertext is that of a network of nodes. Any topology may be supported; hierarchical and non-hierarchical structures are possible, often in the same work. The freedom granted by the ability to make links and create nodes at will often leads to a globally chaotic system with local hierarchies. In part, this is because it is difficult to sustain organizational principles over time and space in a system which makes the creation of links relatively easy (see Missing Context Clues).
In electronic systems, hierarchies are easily implemented using expansion links, which immediately suggest a relationship between the parent and child nodes. Some software packages designed for specific tasks are very explicit in defining possible relationships (eg. IBIS). Others rely on the graphical representation of nodes to indicate relationships such as "contains" and "belongs to" (eg. StorySpace).
Note, in this study we do not use the terms "network" and "LAN" as synonyms.