Network robustness is the capacity for a network to maintain functionality given some perterbation. Network robustness may be modeled in terms of some external perturbation that propagates through the system, destroying links and nodes on its way, in such a case we want to ask how easily does it spread and what is the resistance to its spreading within the network. A network’s robustness is a function of a number of different parameters such as its degree of overall connectivity, the nature of the connections in the system and the overall structure of the network, e.g. is it centralized or distributed, among other factors.