A Kubernetes namespace helps separate a cluster into logical units. It helps granularly organize, allocate, manage, and secure cluster resources. Here are two notable use cases for Kubernetes namespaces:
Apply policies to cluster segments—Kubernetes namespaces let you apply policies to different parts of a cluster. For example, you can define resource policies to limit resource consumption. You can also use container network interfaces (CNIs) to apply network policies that define how communication is achieved between pods in each namespace. Learn more about Kubernetes networking.
Apply access controls—namespaces let you define role-based access control (RBAC). You can define a role object type and assign it using role binding. The role you define is applied to a namespace, and RoleBinding is applied to specific objects within this namespace. Using this technique can help you improve the security of your cluster.