Edge computing service orchestration has emerged as a key research focus to efficiently manage and coordinate heterogeneous resources, applications, and services across distributed edge, fog, and cloud environments. Research papers in this field explore how orchestration frameworks can dynamically allocate computing, storage, and network resources to meet the stringent requirements of latency, energy efficiency, scalability, and reliability for applications such as autonomous driving, smart healthcare, industrial IoT, and immersive media. Studies investigate containerization, microservices, and virtual network function (VNF) orchestration to achieve flexible service deployment and migration. Recent works apply artificial intelligence, reinforcement learning, and game-theoretic approaches for adaptive orchestration, task scheduling, and resource optimization in dynamic edge environments. Security-aware and privacy-preserving orchestration frameworks are also highlighted, focusing on trust management, multi-tenancy, and protection against cyber-attacks. Moreover, blockchain-enabled and federated orchestration models are gaining attention to enhance transparency, decentralization, and collaborative service management. Overall, service orchestration in edge computing is recognized as a cornerstone for enabling seamless, intelligent, and resilient service delivery across highly distributed and heterogeneous infrastructures.