concept

Degree distribution

The curve describing how connectivity is spread across a whole network — how many nodes have one link, how many have ten, how many have thousands. The shape of this curve decides whether a network is robust or fragile. A network where every node has roughly the same degree behaves very differently from one where a few rare hubs hoard most of the links — the second kind (a scale-free network) is both extraordinarily tolerant of random damage and extraordinarily vulnerable to a strike aimed at the hubs.