concept

Modularity (networks)

A network built from dense local clusters — each richly wired inside but only sparsely connected to the others. Modularity acts as a firebreak: damage inside one module tends to stay there, because there are too few links for it to spread to the next. The cost is that the handful of links bridging modules become precious, and the nodes sitting on those bridges — the articulation points — are exactly where the network is most easily split in two. Biological networks are overwhelmingly modular, which is a large part of why they localize damage so well.