The document provides an overview of microservices and a microservices pattern language. It discusses how the monolithic architecture can become difficult to manage for large applications. Microservices help address this issue by decomposing applications into smaller, independent services. However, microservices also introduce new complexities in developing and operating distributed systems. The microservices pattern language provides proven solutions to common problems when architecting microservice applications. It covers patterns for service decomposition, communication, data consistency, deployment, and other concerns. The pattern language guides architectural decisions for microservice applications.