A node has high betweenness centrality if it serves as an intermediate between many other nodes, that is, it lies
between them with respect to their shortest path.. In other words if we calculate the total set of shortest paths, then a
node with high betweenness centrality is present with a large proportion of this set. Again, the higher this metric is,
the more important the node is, since it controls the flow of information between many other nodes (Newman M.,
2002). Closeness centrality and it’s study has special meaning when studying fault tolerance or attacks in networks.
If a node with high closeness centrality is affected, then the overall impact on the connectivity and distances on the
network is severe. Although this metric is quote important, it is rather expensive to compute, especially in large
networks, since it requires global information for the network examined. Recent algorithms try to minimize this
complexity (Brandes U., 2001) (Newman M., 2001), so closeness centrality and its study provides us with very
important results.