# Temporal Namespace

> A Namespace is a unit of isolation within the Temporal Platform that provides resource separation, Workflow ID uniqueness, and configuration boundaries.

> **ℹ️ Info:**
> Open source and Temporal Cloud
> This page covers core namespace concepts that apply to both open source Temporal and Temporal Cloud.
>
> Temporal Cloud namespaces include additional capabilities, such as [API key](/cloud/api-keys) and [mTLS authentication](/cloud/certificates), [built-in role-based access controls](/cloud/manage-access/roles-and-permissions#namespace-level-permissions), [high availability replication](/cloud/high-availability), and [namespace tags](/cloud/namespaces#tag-a-namespace).
>
> Moving from self-hosting to Cloud, or the reverse, requires zero code changes and incurs zero downtime.

A Namespace is a unit of isolation within the [Temporal Platform](/temporal#temporal-platform).

[Task Queues](/task-queue) and [Workflow Executions](/workflow-execution) belong to a Namespace.
When a Workflow Execution is spawned, it does so within a specific Namespace.

## Usage

- **Workflow ID uniqueness**: Temporal guarantees a unique Workflow Id within a Namespace.
  Workflow Executions may have the same Workflow Id if they are in different Namespaces.
- **Resource isolation**: Heavy traffic from one Namespace will not impact other Namespaces running on the same Temporal Service.
- **Configuration boundaries**: Options like the [Retention Period](/temporal-service/temporal-server#retention-period) and [Archival](/temporal-service/archival) destination are configured per Namespace.
- **Default Namespace**: If no Namespace is specified, the Temporal Service uses the Namespace "default" for all Temporal SDKs and the Temporal CLI.
  You must create a Namespace before using it in your Client.
- **Multi-tenancy**: A single Namespace is still multi-tenant.
  Multiple applications or teams can share a Namespace, but must coordinate on Workflow ID and Task Queue naming to avoid conflicts.

## Namespace operations

For how to create and manage Namespaces:

- **Open source Temporal**: [Managing Namespaces](/self-hosted-guide/namespaces)
- **Temporal Cloud**: [Temporal Cloud Namespaces](/cloud/namespaces)