Related Pages
Related Pages are linked to the page you're on by recent click traffic (i.e. a form of collaborative filtering).
In other words, they're an additional type of link between pages, left by users as they move about.
In the Related Pages section at the bottom of each page, font size shows the amount of connecting traffic and colour shows the time since last edit, in this case the redder the link, the more recently it was edited. This way, you can see what's happening local to the page you're on - important tacit knowledge.
As people (here, the registered users) click about looking at things (either through the Related Pages section or any other way), connections are made or strengthened, old unvisited ones are lost, and wiki pages spread about finding useful places to come to life.
This produces far more efficient mixing than simply relying on fixed links in pages, users sending links to their friends, teachers telling students to go and have a look at something etc. This helps to stop things converging too much (see Filter bubbles).
It also produces more direct feedback between users and content (and between users), with the capacity to learn in a similar way to Artificial Intelligence and for communities of users to co-learn.
