Kubernetes is leading software in container orchestration. Kubernetes works by managing clusters, which is simply a set of hosts meant for running containerized applications. In order to have a Kubernetes cluster, you need a minimum of two nodes - a master node and a worker node. Of course, you can expand the cluster by adding as many worker nodes as you need.
This is a companion discussion topic for the original entry at https://linuxconfig.org/how-to-install-kubernetes-on-ubuntu-20-04-focal-fossa-linux