---
source: https://iinventedlight.com/library/notes/kubernetes-namespaces.md
title: "Kubernetes namespaces"
license: CC-BY-4.0
license_url: https://creativecommons.org/licenses/by/4.0/
source_license: "CC BY 4.0 (kubernetes/website); prose restates cited source lines"
attribution: "Summary by iinventedlight (AI-assisted). Sources: Kubernetes Authors, Namespaces, CC BY 4.0 (kubernetes/website); Kubernetes Authors, Share a Cluster with Namespaces, CC BY 4.0 (kubernetes/website)."
author: "iinventedlight (synthesis of cited sources); text drafted with AI assistance"
date: 2026-11-04
status: published
checked_on: 2026-11-04
as_of: 2026-11-04
confidence: medium
untested: "No code was run for this note; only the fetched documentation pages were read."
category: coding-references
topic_area: "code-ai-eng: Kubernetes"
tags: kubernetes, namespaces
sources:
  - id: S1
    title: "Namespaces"
    publisher: Kubernetes Authors
    url: https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/
    accessed: 2026-11-04
    license: "CC BY 4.0 (kubernetes/website)"
  - id: S2
    title: "Share a Cluster with Namespaces"
    publisher: Kubernetes Authors
    url: https://kubernetes.io/docs/tasks/administer-cluster/namespaces/
    accessed: 2026-11-04
    license: "CC BY 4.0 (kubernetes/website)"
---
# Kubernetes namespaces

## Short answer
Namespaces split one cluster into groups of resources. Names must be unique inside a namespace but not across namespaces, and namespaces cannot nest.

## Built-in namespaces
- `default` for objects with no other namespace. [S2]
- `kube-system` for objects the Kubernetes system creates. [S2]
- `kube-public` readable by everyone, and `kube-node-lease` for node heartbeats. [S2]

For production, create your own namespaces instead of using `default`, and avoid the reserved `kube-` prefix. [S1]

## Claims
- id: C1
  claim: Namespaces isolate groups of resources within a single cluster.
  source: S1
  evidence: "namespaces provide a mechanism for isolating groups of resources within a single cluster"
- id: C2
  claim: Avoid creating namespaces with the prefix kube-.
  source: S1
  evidence: "Avoid creating namespaces with the prefix kube-"
- id: C3
  claim: default is the namespace for objects with no other namespace.
  source: S2
  evidence: "The default namespace for objects with no other namespace"
- id: C4
  claim: kube-system holds objects created by the Kubernetes system.
  source: S2
  evidence: "The namespace for objects created by the Kubernetes system"

## Sources
- [S1] Namespaces. Kubernetes Authors. https://kubernetes.io/docs/concepts/overview/working-with-objects/namespaces/ . License: CC BY 4.0 (kubernetes/website). Accessed 2026-11-04.
- [S2] Share a Cluster with Namespaces. Kubernetes Authors. https://kubernetes.io/docs/tasks/administer-cluster/namespaces/ . License: CC BY 4.0 (kubernetes/website). Accessed 2026-11-04.

License: this note is CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Summary by iinventedlight (AI-assisted).