Graph theory is one of the many objects of discrete mathematics. Discrete mathematics studies graph theory by means of graphs, but graph theory is a theory, and other disciplines also have their own research methods (such as data structure and graph theory). In any case, all disciplines retain the basic concepts of graph theory (directed and undirected, point set, edge set, loop, shortest path and so on). ) and algorithm theory (Dijkstra, Minimum Spanning Tree, DFS, etc. ).

Combinatorial mathematics, also known as discrete mathematics.

Combinatorial mathematics in a broad sense is discrete mathematics, and combinatorial mathematics in a narrow sense is the general name of graph theory, algebraic structure, mathematical logic and so on. But this is only the difference between different scholars. In a word, combinatorial mathematics is a science that studies discrete objects. With the development of computer science, the importance of combinatorial mathematics is increasingly prominent, because the core content of computer science is to process discrete data with algorithms.