graphs often it is useful to represent information in more general graphical form than considered so farsuch as the following representation of the distances between townsglasgow edinburgh newcastle manchester birmingham swansea london exeter with similar structures (maybe leaving out the distancesor replacing them by something else)we could represent many other situationslike an underground tunnel networkor network of pipes (where the number label might give the pipe diameters)or railway mapor an indication of which cities are linked by flightsor ferriesor political alliances even if we assume it is network of paths or roadsthe numbers do not necessarily have to represent distancesthey might be an indication of how long it takes to cover the distance in question on footso given distance up steep hill would take longer than on even ground there is much more that can be done with such picture of situation than just reading off which place is directly connected with another placefor examplewe can ask ourselves