Nodes and links

The web = nodes and links
Google = nodes and links
MySpace = nodes and links
LinkedIn = nodes and links
Facebook = nodes and links
Your work organization = nodes and links
Your offline life = nodes and links
The map = nodes and links
Your project plan = nodes and links
Your brain = nodes and links

What is not nodes and links?
Are the nodes different? Are the links different?

Should your brain cells avoid bad neighbourhoods to get top rankings?