In a computer network, each computer/router is a node and the cables between them are the edges. The following image illustrates some possible topologies used for a computer network (credit: https://commons.wikimedia.org/wiki/File:NetworkTopologies.svg):
You can now draw the parallel with the graph definition we discovered in the last section. Here again, the graph structure helps in answering some common questions you may ask yourself about your network:
- How fast will this information be transferred from A to B? This sounds like a shortest path issue.
- Which of my nodes is the most critical one? By critical, we mean that if this node is not working for some reason, the whole network will be impacted. Not all nodes have the same impact on the network. That's where centrality algorithms come into the game (see Chapter 6, Node Importance).
