# Entity description

> A dataclass with the fixed properties of an entity, like its key, translation key, and device class, so many similar entities can share one class.

Source: https://contributors.home-assistant.io/glossary/entity-description/

- In code: `EntityDescription`, `SensorEntityDescription`
- Also: entity descriptions

An integration with twenty sensors usually has one sensor class, and a list of twenty entity descriptions. Each description says what is different about one sensor.

## Related terms

- [Entity](https://contributors.home-assistant.io/glossary/entity/): One thing Home Assistant can show, measure, or control, like a light, a temperature sensor, or a switch. Every entity has a state.
- [Device class](https://contributors.home-assistant.io/glossary/device-class/): What an entity measures or is, like `temperature` or `door`. It sets the icon, the units, and how the frontend shows the entity.
- [Translation key](https://contributors.home-assistant.io/glossary/translation-key/): The key that points to a text in an integration's `strings.json`, so the text can be translated. Integrations use keys, not English text in the code.