This document is a comprehensive survey of the Grey Wolf Optimizer (GWO), a meta-heuristic algorithm inspired by the social hunting behavior of grey wolves, highlighting its significance in swarm intelligence and various optimization problems across engineering fields. It reviews foundational concepts, algorithm structure, hybridizations with other optimization techniques, and specific applications, underscoring the adaptability and effectiveness of GWO in solving complex real-world challenges. The paper serves as a guide for researchers and developers intending to utilize GWO for diverse optimization tasks.