Compose 514 runs BookNest on one host. Swarm 514 mode, built into Docker Engine 514 , runs the same kind of file across a cluster of hosts: it schedules containers onto nodes, keeps the requested number running, spreads traffic over them and rolls out updates. This section builds a real three-node swarm, deploys BookNest to it, and then puts Swarm honestly beside Kubernetes 5,150 , which Kubernetes covers in depth.