Graph

A graph is made out of nodes and directed edges which define a connection from one node to another node.

A node (or vertex) is a discrete position in a graph. Edges can be directed an undirected. Edges have an associated distance (also called costs or weight). The distance between two nodes a and b is labeled as [a,b].

The mathematical description for graphs is G= {V,E}, meaning that a graph is defined by a set of vertexes (V) and a collection of edges.

The order of a graph is the number of nodes. The size of a graph is the number of edges.