# Registry

> Where Home Assistant keeps what it knows about entities, devices, areas, floors, and labels, and what users changed about them.

Source: https://contributors.home-assistant.io/glossary/registry/

- In code: `er.async_get`, `dr.async_get`, `entity_registry`, `device_registry`
- Also: registries, entity registry, device registry

There is one registry for each: the entity registry, the device registry, the area registry, and so on. They are stored in `.storage` and survive restarts.

Users' changes live in the registries, not in integrations. When a user renames an entity, the integration does not need to know.

## Related terms

- [Unique ID](https://contributors.home-assistant.io/glossary/unique-id/): An ID that an integration gives an entity or config entry, which never changes, so Home Assistant recognizes it after a restart.
- [Device](https://contributors.home-assistant.io/glossary/device/): A physical device, or a service, that one or more entities belong to, like a thermostat with a temperature sensor and a humidity sensor.
- [Area](https://contributors.home-assistant.io/glossary/area/): A room or space in the home, like the kitchen, that devices and entities belong to.
- [Label](https://contributors.home-assistant.io/glossary/label/): A tag users put on entities, devices, areas, automations, and more, to group them their own way, like everything that uses a lot of energy.