The hub and authority model

Found a good explainatiion on the "Hub and Authority" model in SEO: Authority development, hub and authority model optimisation - The Kolberg Partnership UK Search engines are always looking for ways to make sense of the web. One way that search engines decide which sites should rank higher is by using a model of hubs and authorities. Authorities are websites that are considered to be the central sources of high quality information on a given topic, while hubs are identified as websites that point to and 'hook up' several authorities through their linking patterns. This method is more effective than using a system based only on link popularity to determine relevance and is much more difficult to manipulate. A site that is recognised as an authority in its field will always outrank other sites that may contain the same kind of information.