Glossary


The glossary covers terms which are used around Home Assistant.

Action

An Action is an event that can be fired as a response to a trigger, once all conditions have been met.

Add-on

Add-ons are additional standalone third-party software packages that can be installed on Home Assistant OS. Most of these, add-on provided, applications can be integrated into Home Assistant using integrations. Examples of add-ons are: an MQTT broker, database service or a file server.

Automation

Automations connect one or more triggers to one or more actions in a ‘when trigger then do action’ fashion with additional optional conditions. For example, an automation might connect the trigger ‘sunset’ to the action ‘turn the lights on’ but only if the condition ‘someone is home’ is met. Pre-made automations for common use-cases are available via the blueprints feature.

Binary sensor

A binary sensor returns information about things that only have two states - such as on or off.

Component

Integrations (see below) used to be known as components.

Condition

Conditions are an optional part of an automation that will prevent an action from firing if they are not met.

Cover

Covers are devices such as blinds, garage doors, etc that can be opened and closed and optionally set to a specific position.

Customize

Customization allows you to overwrite the default parameters of your devices in the configuration.

Device

A device is a named collection of entities that all represent the same physical/logical unit, which can do or observe something. An example for a device would be a smart plug named ‘Coffee Machine’ which provides a switch entity plus one or more sensor entities for power monitoring or similar.

Device tracker

Device trackers are used to track the presence, or location, of a device.

Discovery

Discovery is the automatic setup of zeroconf/mDNS and uPnP devices after they are discovered.

Domain

Each integration in Home Assitant has a unique identifier: a domain. All of the entities and services available in Home Assistant are provided by integrations and thus belong to such a domain. The first part of the entity or service, before the . shows the domain they belong to. For example light.kitchen is an entity in the light domain from the light integration, while hue.activate_scene is the activate_scene service for the hue domain which belongs to the Hue integration.

Entity

An entity is the representation of a single control or data point of a device or service inside Home Assistant. A single device or service can thus provide multiple entities to be able to monitor and control all features a device provides. For example, a combined temperature and humidity sensor, in general, provides two sensor entities. One for the temperature (e.g., sensor.temperature with state 21.0 and unit °C) and one for the humity (e.g., sensor.humidity with state 65.4 and unit %).

Event

An event is when something happens.

Frontend

The frontend is a necessary component for the UI, it is also where you can define your themes.

Group

Groups are a way to organize your entities into a single unit.

HASS

HASS or hass is often used as an abbreviation for Home Assistant. It is also the command-line tool.

HassOS

Another name for Home Assistant Operating System

Home Assistant Core

Home Assistant Core is a Python program. It can be run on various operating systems and is the basis for Home Assistant. When people are talking about Home Assistant Core they usually refer to a standalone installation method that can be installed using a Virtual Environment or Docker. Home Assistant Core does not use the Home Assistant Supervisor.

Home Assistant Operating System

Home Assistant OS, the Home Assistant Operating System, is an embedded, minimalistic, operating system designed to run the Home Assistant ecosystem on single board computers (like the Raspberry Pi) or Virtual Machines. The Home Assistant Supervisor can keep it up to date, removing the need for you to manage an operating system.

Home Assistant Supervised (Previously Hass.io)

Home Assistant Supervised is a full UI managed home automation ecosystem that runs Home Assistant, the Home Assistant Supervisor and add-ons. It comes pre-installed on Home Assistant OS, but can be installed on any Linux system. It leverages Docker, which is managed by the Home Assistant Supervisor.

Home Assistant Supervisor

The Home Assistant Supervisor is a program that manages a Home Assistant installation, taking care of installing and updating Home Assistant, add-ons, itself and, if used, updating the Home Assistant Operating System.

Integration

Integrations connect and integrates Home Assistant with devices, services, and more. Such an integration contains all the logic that takes care of vendor- and device-specific implementations such as authentication or special protocols and brings those into Home Assistant in a standardized way. For example, the Hue integration integrates the Philips Hue bridge and its connected bulbs into Home Assistant, making them available as Home Assistant light entities you can control.

Light

A light has a brightness you can control, and optionally color temperature or RGB color control.

Lovelace

Lovelace is the original code name of the UI that is now known as Home Assistant dashboards.

Notification

You can use notifications to send messages, pictures, and more, to devices.

Packages

Packages allow you to bundle different component configurations together.

Platform

Platforms are building blocks provided by some integrations to be used by other integrations. For example, the Light integration provides the light platform that is utilized by all integrations providing light entities such as e.g. Hue.

Scene

Scenes capture the states you want certain entities to be. For example, a scene can specify that light A should be turned on and light B should be bright red.

Script

Scripts are components that allow users to specify a sequence of actions to be executed by Home Assistant when turned on.

Selectors

Selectors are components for the user interface. Some selectors can, for example, show a toggle button to turn something on or off, while another select can filter a list of devices to show only devices that have motion-sensing capabilities.

Sensor

Sensors return information about a thing, for instance the level of water in a tank.

Service

Services are called to perform actions.

Switch

Switches are things that have two states you can select between, such as turning on or off a socket.

TTS

TTS (text to speech) allows Home Assistant to talk to you.

Template

A template is an automation definition that can include variables for the service or data from the trigger values. This allows automations to generate dynamic actions.

Trigger

A trigger is a set of values or conditions of a platform that are defined to cause an automation to run.

Variables

Variables are used to store values in memory that can be processed e.g. in a script.

Zone

Zones are areas that can be used for presence detection.