### Question

In the context of this exercise, what are other examples of things that graphs can model?

### Answer

Graphs can be used to model social networks, like Facebook, where each person is a vertex, and the edges are the connections or relationships between people.

Graphs can also model subway systems or airport systems. Each vertex can be a stop or an airport, and the edges are routes between the locations.

Graphs can even model more abstract ideas, such as neural networks, where each vertex is a neuron, and the edges are the connections between them.