A graph is a structure that can be characterized as a set of objects called vertices (also nodes) that are connected by edges.

Examples of things that can be represented as graphs:

	Vertices	Edges
Maps	Cities	Roads
Circuits	Transistors	Wires
Networks	Computers	Cables
UML Diagrams	Classes	Class Relationships
FWGC Problem	States	Moves

Trees (for example, binary search trees) are special cases of graphs.