# Definition:Graph (Graph Theory)/Informal Definition

## Informal Definition

A graph is intuitively defined as a pair consisting of a set of vertices and a set of edges.

### Vertex

Let $G = \struct {V, E}$ be a graph.

The vertices (singular: vertex) are the elements of $V$.

Informally, the vertices are the points that are connected by the edges.

In the above, the vertices (singular: vertex) are the points $A, B, C, D, E, F, G$ which are marked as dots.

### Edge

Let $G = \struct {V, E}$ be a graph.

The edges are the elements of $E$.

In the above, the edges are $AB, AE, BE, CD, CE, CF, DE, DF, FG$.