This document provides an overview of ant colony optimization (ACO), a metaheuristic algorithm inspired by the behavior of ants. It describes how ants lay pheromone trails between their colony and food sources, preferentially following dense trails and reinforcing short paths. The ACO algorithm applies this behavior to optimization problems by having "ants" probabilistically construct solutions and adjust pheromone levels to guide future construction. The document outlines the ACO process, defines its parameters, provides a sample traveling salesman problem implementation, and discusses advantages like retaining colony memory and disadvantages like difficulty of analysis.