The fundamental underlying idea of scheduling is based on the labels of nodes in Kubernetes. The built-in scheduler and any custom schedulers are expected to check the specification of the nodes from their labels. With this idea, there are some
integrated node labels, such as the following ones:

kubernetes.io/hostname
failure-domain.beta.kubernetes.io/zone
failure-domain.beta.kubernetes.io/region
beta.kubernetes.io/instance-type
beta.kubernetes.io/os
beta.kubernetes.io/arch 

These labels and their values are assigned by the cloud providers, but do note that label values are not standardized yet. For Minikube, there is only one master node, and its labels can be checked with the following command:

$ kubectl get nodes --show-labels
NAME STATUS ROLES AGE VERSION LABELS
minikube Ready master 9m v1.10.0 beta.
kubernetes.io/arch=amd64,beta.kubernetes.io/os=linux,kubernetes.
io/hostname=minikube, node-role.kubernetes.io/master=

As highlighted, the node with the hostname minikube has an architecture of amd64 with an operating system, linux, and its node-role is master.