This document discusses different architectural styles and patterns for integration including service-oriented architecture (SOA) and microservices. It describes SOA components like services, service bus, and service repository. It then explains how Mule ESB can be used to componentize microservices with API policies. The benefits are scalability, reusability and service independence while the downside is longer initial development time. Microservices architecture is described as taking a lightweight distributed approach compared to heavyweight monolithic systems, with minimal centralized management. Common integration patterns are also listed.