• A graph G(V,E) is two sets of object
– Vertices (or nodes), set V
– Edges, set E
• A graph is represented with dots or circles (vertices) joined by lines (edges)
• The magnitude of graph G is characterized by number of vertices |V|(called the order of G) and number of edges |E| (size of G)
• The running time of algorithms are measured in terms of the order and size