''From CategoryNetwork and CategoryHierarchy:'' ---- The internet is both a network and a hierarchy. When you 'surf' the internet.... follow the links...... follow the connections..... that's when you are using the Internet in its network form. * Can't we follow a link and at the same time have a hierarchy change? In my opinion, this is also possible. You only have to use a "hierarchy changing link". More info is here: http://www.usemod.com/cgi-bin/mb.pl?HierarchicLinking and here: http://www.usemod.com/cgi-bin/mb.pl?TonyArmani. -- TonyArmani When you type in a URL directly or use a search engine, you are using the internet in its hierarchical form. ''This is generally at a more local level, usually a server level. However, the directories/folders may be virtual and point somewhere else. The internet protocols do not dictate that one uses hierarchies, I would note.'' ---- It is possible for a node in a network to be one of its own ancestors. A network has no top and no bottom. The simplest data structure is a linear one (like an array, or a linked list). A hierarchical data structure is more complex than a linear data structure. In a way, a hierarchy is 'half-linear'. There is always a unique, linear path back to the root, but if you start at the root then there is more than one path you can follow. ''More importantly, in a '''hierarchy''' there is a single linear path between the root and any node - really, between any two nodes - while in a '''network''' there may be multiple paths.'' -- GeoffSobering A network is the most complex and non-linear data structure. The human brain is a network. The wiki is a network... ''Or, perhaps, the Internet is a pure network and DNS imposes a hierarchy to assist navigating the network? But even then, it's entirely possible to have mail.domain.com and mail.domain.net reference the same IP, breaking the rules of hierarchy.'' The internet is a hierarchy implementation-wise. DNS ''exposes'' the underlying hierarchy in order to fit in with ''corporate hierarchies''. The hierarchical preferences of DNS have nothing to do with assisting users, let alone user navigation, in any way, shape or form. ---- Unix files and Unix processes are organized hierarchically. IP addresses and Domain Names are organized hierarchically. All human societies are organized hierarchically. ''False.'' Can anybody imagine a society that is based on a network rather than a hierarchy? * I sense a John Lennon song about to burst forth.... ''Um, yes... a group of friends come to mind. A less trivial example includes any structure where differing members are responsible for differing areas, where those areas affect all members. Such a structure only becomes hierarchial if you cut links, which only demonstrates that'' any ''graph can be made hierarchal if one cuts enough links.'' ''Also, would not an anarchy be a network, pretty much by definition? If you reject a hierarchy as a model of society, and you don't reject relationship between people, you're going to have a network.'' ''-- cwillu'' Yes. ''In practice, most democracies (or semi-democracies) are not hierarchical. They have hierarchical elements or tendencies, but it's a complex relationship. The president has checks on him from two other branches and voters. And then you have private companies, non-profit organizations, and special-interest groups. It's a complex structure. Generally when things have to get done in a hurry, such as an emergency, hierarchies seem the most effective. However, they don't work so well for innovation and complex tasks.'' ---- See also: LimitsOfHierarchies, SetTheory ---- CategoryHierarchy, CategoryOrganization, CategoryClassification