# Hierarchy

AppBarn uses one containment hierarchy:

`Workspace → Project → App → Environment → Build`

- **Workspace** owns people, plan and quotas.
- **Project** groups Apps and is a primary authorization scope.
- **App** represents one mobile application.
- **Environment** is a named release lane such as `staging` or `production`.
- **Build** is an immutable uploaded artifact plus parsed identity, checksum, provenance and release notes.

IDs are canonical UUIDv4 values. Names are display values and are never authority selectors.

Deleting or archiving parents is lifecycle-guarded; retained Builds are never silently cascaded away.

## Related

- [Access](/concepts/access)
- [Builds](/concepts/builds)
- [Environments](/reference/environments)