A Node is a machine, typically running Linux, that has been added to the Kubernetes cluster. It can be a physical machine or a virtual machine. In the case of minikube, it is a single virtual machine that is running all the software for Kubernetes. In larger Kubernetes clusters, you may have one or several machines dedicated to just managing the cluster and separate machines where your workloads run. Kubernetes manages its resources across Nodes by tracking their resource usage, scheduling, starting (and if needed, restarting) Pods, as well as coordinating the other mechanisms that connect Pods together or expose them outside the cluster.
Nodes can (and do) have metadata associated with them so that Kubernetes can ...