Clusters bring together websites that are linked either by content, or format, or both.
Hubs are entry ways to the clusters. They are short websites that describe the nature of the cluster they subsume, and describe features that are common to the subsumed websites.
The chart below gives an overview of all the websites in the system.
Hubs are highlighted in green.
Each rectangular cell refers to a website.
Each column refers to a cluster of websites.