graph theory
noun
Definitions
The branch of mathematics dealing with the properties of graphs (networks of vertices and edges).
Example: The type of graph studied in graph theory is formally described as an ordered pair G=(V, E) comprising a set V of vertices, or nodes, and a set E of pairs (either ordered or unordered) of vertices, each representing an (directed or undirected) edge; if desired, the vertices and/or edges can be labelled.
(applied mathematics) A theory developed by applying graph theory to a particular problem or application.