Upgrading the Kubernetes cluster is done in two phases. You first upgrade the control plane nodes and then the worker nodes. It is possible to upgrade to the next minor release or to any other next patch release of the same minor release. For example, when your cluster is using the version 1.18.6, you could upgrade to 1.18.p where p >= 7 and to 1.19.x (whatever the value of x), but not to 1.20.x.
As the control plane and workers are running on host systems, you will also need to upgrade these systems. You will see how to prepare ...
