This document provides an overview of discrete mathematics. It discusses key areas like graph theory, counting and probability, social choice, and coding/encryption. Graph theory is used to model problems like finding efficient routes. Counting and probability help answer questions about outcomes and events. Social choice examines voting methods and fair division. Identification numbers, codes, and barcodes are important applications in the digital world. Discrete math provides tools and models for problems in business, industry, and computer science.