Orchestration is about running containerized apps across multiple servers--a cluster of servers. You use the same Docker images, and you can use the same Docker Compose file format, but instead of managing containers yourself, you tell the cluster what you want the end result to be, and it manages containers for you. In this part of the book you’ll learn how to use Docker Swarm, which is a simple and powerful orchestrator built into Docker. You’ll learn about the application update and rollback process, and how to connect your build pipeline to the cluster to add continuous deployment to your CI pipeline.