## 1.2 Further Concepts for Network Graphs

Note: if you cannot remember the basics of network graphs, revise notes for 1.1 Basics of Network Graphs.

### Simple Graph

- Graphs which
**do not contain loops or duplicate edges**(i.e. there are no two vertices connected directly by more than one edge). - Each vertex has a
**maximum degree**of n-1. - A simple graph has a
**maximum number of edges**of \frac {n(n-1)}{2}. - Graphs which contain loops or duplicate edges are sometimes called
**multigraphs.**

Example