The difference between vertices and edges [Graphs, algorithm and DS]

Question

I just started reading the book Algorithms, which defined graphs as follows:

Graphs - which represent the relationship between arbitrary pairs of objects. Figure 1.8 (b) models the road network as a graph, where the tops of the city and the edges are roads connecting pairs of cities. The graphs are probably the object in question whenever you are looking for a “network”, “chain”, “web” or “relationship”.

Figure 1.8 (b) is as follows:

The following line bothers me:

... where the peaks are cities and territories - these are roads connecting pairs of cities ...

Answer 1

- , - . .

, , .

(), "" , . " ", , , / /: , , "--" ..

"" , (.. ), " ". (, ), " ", "", .

, . "" Cormen et al. , , , , , , - .

Answer 2

- . - , .

Answer 3

if u counts every row u see, thats vertices.edges are angles [for example, a sphere has no angles and no vertices, but it has face i. If you want to know all the properties of 3D shapes, finding 3D shapes on your .u computer will get more explanations.