This chapter demonstrated why orchestrators are needed in the first place, and how they conceptually work. It pointed out which orchestrators are the most prominent ones at the time of writing, and discussed the main commonalities and differences between the various orchestrators.
The next chapter will introduce Docker’s native orchestrator, SwarmKit. It will elaborate on all the concepts and objects that SwarmKit uses to deploy and run a distributed, resilient, robust, and highly available application in a cluster—on-premises or in the cloud.