The glossary covers terms which are used around Home Assistant.


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


Add-ons provide additional, standalone, applications that can run beside Home Assistant. 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.


Automations offer the capability to call a service based on a simple or complex trigger. Automation allows a condition such as a sunset to cause an event, such as a light turning on.

Binary sensor

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


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


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


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


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


A device is usually a physical unit which can do or observe something.

Device tracker

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


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


Entities and services belong to a domain, which is the first part of the entity or service, before the .. For example is an entity in the light domain, while homeassistant.turn_on is the turn_on service for the homeassistant domain.


An entity is the representation of a function of a single device, unit, or web service. There may be multiple entities for a single device, unit, or web service, or there may be only one.


An event is when something happens.


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


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


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


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

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.


Integrations provide the core logic for the functionality in Home Assistant. Like notify provides sending notifications.


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


Lovelace is the name of the current frontend.


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


Packages allow you to bundle different component configurations together.


Platforms make the connection to a specific software or hardware platform. For example, the pushbullet platform works with the service to send notifications.


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.


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


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


Services are called to perform actions.


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


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


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.


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


Zones are areas that can be used for presence detection.