A hub is a component of a network with a high-degree [[Vertex (graph theory)|node]]. Hubs have a significantly larger number of links in comparison with other nodes in the network. The number of links ([[Degree (graph theory)|degrees]]) for a hub in a scale-free network is much higher than for the biggest node in a random network, keeping the size ''N'' of the network and average degree ''<k>'' constant. The existence of hubs is the biggest difference between random networks and scale-free networks. In random networks, the degree ''k'' is comparable for every node; it is therefore not possible for hubs to emerge. In scale-free networks, a few nodes (hubs) have a high degree ''k'' while the other nodes have a small number of links. | A hub is a component of a network with a high-degree [[Vertex (graph theory)|node]]. Hubs have a significantly larger number of links in comparison with other nodes in the network. The number of links ([[Degree (graph theory)|degrees]]) for a hub in a scale-free network is much higher than for the biggest node in a random network, keeping the size ''N'' of the network and average degree ''<k>'' constant. The existence of hubs is the biggest difference between random networks and scale-free networks. In random networks, the degree ''k'' is comparable for every node; it is therefore not possible for hubs to emerge. In scale-free networks, a few nodes (hubs) have a high degree ''k'' while the other nodes have a small number of links. |