Pods are collected into namespaces, which are used to group Pods together for a variety of purposes. You already saw one example of namespaces when we asked for the status of all the Pods in the cluster with the --all-namespaces option earlier.
Namespaces can be used to provide quotas and limits around resource usage, have an impact on DNS names that Kubernetes creates internal to the cluster, and in the future may impact access control policies. If no namespace is specified when interacting with Kubernetes through kubectl, the command assumes you are working with the default namespace, named default.
