In
graph theory, the
degree (or
valency) of a
vertex of a
graph is the number of
edges incident to the vertex, with
loops counted twice. The degree of a vertex
![](http://info.babylon.com/onlinebox.cgi?rt=GetFile&uri=!!ARV6FUJ2JP&type=0&index=1722)
is denoted
![](http://info.babylon.com/onlinebox.cgi?rt=GetFile&uri=!!ARV6FUJ2JP&type=0&index=2423)
or . The
maximum degree of a graph
G, denoted by Δ(
G), and the
minimum degree of a graph, denoted by δ(
G), are the maximum and minimum degree of its vertices. In the graph on the right, the maximum degree is 5 and the minimum degree is 0. In a
regular graph, all degrees are the same, and so we can speak of
the degree of the graph.