Graph Definitions

• Order: Number of vertices or nodes, $|V|$
• Size: Number of edges of a graph, $|E|$
• Path: A walk which does not repeat edges or nodes
• Trail: A walk which can repeat nodes but not edges
• Walk: A sequence of nodes/edges in a graph
• Diameter: The number of edges in the longest, shortest path between any pair of nodes. The diameter of a disconnected graph is always infinity.