Summary
This chapter introduced you to namespaces, which are extremely important in Kubernetes. You cannot manage your cluster effectively without using namespaces because they provide logical resource isolation in your cluster. Most people use production and development namespaces, for example, or one namespace for each application. It is generally not rare to see clusters where dozens of namespaces are created.
We discovered that most Kubernetes resources are scoped to a namespace, though some are not. Keep in mind that, by default, Kubernetes is set up with a few default namespaces, such as kube-system, and that it is generally a bad idea to change the things that run in these namespaces, especially if you do not know what you are doing.
We also discovered that namespaces can be used to set quotas and limit the resources that Pods can consume, and it is a really good practice to set these quotas and limits at the namespace level using the ResourceQuota and LimitRange objects...