Service-Oriented Architecture (SOA) is a strategic design framework that organizes software applications into a collection of loosely coupled services, enabling seamless integration and communication over a network. This approach enhances system agility by breaking down monolithic applications into modular, reusable components, thereby promoting efficiency and reducing redundancy. SOA is widely adopted across various industries, such as e-commerce, finance, and healthcare, to streamline operations and improve customer experience. It facilitates better interoperability and flexibility, allowing organizations to respond swiftly to changing business requirements. Key principles of SOA include interoperability, loose coupling, and abstraction, which foster collaboration and innovation while maintaining system scalability and adaptability. Challenges such as complexity, performance overhead, and governance must be managed to leverage SOA's full benefits. The advent of microservices architecture represents an evolution of SOA principles, emphasizing decentralized management and lightweight, independently deployable services to align with modern software delivery practices.