Discrete mathematics is a mathematical discipline that studies discrete structures and their relationships. It is widely used in computer science, communication engineering, graph theory and combinatorial optimization, operational research and other fields. The following are some application fields of discrete mathematics:

-Computer science: programming languages, data structures, operating systems, compilation techniques, artificial intelligence, databases, algorithm design and analysis, etc.

Communication engineering: coding theory, channel coding and modulation.

-Graph theory and combinatorial optimization: shortest path problem, minimum spanning tree problem, etc.

-operational research: linear programming, integer programming, etc.