Don't get the network diagram

I’m trying to understand the significance of the connections formed with the network diagram and how I would use them. I clearly understand that the nodes correspond more or less to the topics in the left-hand pane. I assume that the colors of the nodes indicate relevance although there is no legend that explains what a blue node is. I also see that clicking on a node “recenters” the focus to that node. What I don’t understand is what I am supposed to conclude from the newly-highlighted links from the recentered node pointing to other nodes. I thought I might “travel” deeper through a path based on successive nodes, but the paths simply change based on the new re-centered node. What am I missing or not seeing? How do others use this feature?

Choose “Help > DEVONagent Help > Searching The Web” and finally click on the quick link “Digest Tab”. This section explains e.g. the colors.

I find this mind maps very useful and illustrative. I wish there was an easy way to save them. What I do is screen capture and then include them in my “search” reports.