- topic: Action
  description: "An [Action](/docs/automation/action/) is an event that can be fired as a response to a trigger,  once all conditions have been met."
- topic: Add-on
  description: "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."
- topic: Automation
  description: "[Automations](/docs/automation/) 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](/docs/automation/using_blueprints/)."
- topic: Binary sensor
  description: "A [binary sensor](/integrations/binary_sensor) returns information about things that only have two states - such as on or off."
- topic: Component
  description: "Integrations (see below) used to be known as components."
- topic: Condition
  description: "[Conditions](/docs/scripts/conditions/) are an optional part of an automation that will prevent an action from firing if they are not met."
- topic: Cover
  description: "[Covers](/integrations/cover) are devices such as blinds, garage doors, etc that can be opened and closed and optionally set to a specific position."
- topic: Customize
  description: "[Customization](/docs/configuration/customizing-devices/) allows you to overwrite the default parameters of your devices in the configuration."
- topic: Device
  description: "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."
- topic: Device tracker
  description: "[Device trackers](/integrations/device_tracker) are used to track the presence, or location, of a device."
- topic: Discovery
  description: "[Discovery](/integrations/discovery/) is the automatic setup of zeroconf/mDNS and uPnP devices after they are discovered."
- topic: Domain
  description: "Each integration in Home Assistant 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](/integrations/light), while `hue.activate_scene` is the `activate_scene` service for the `hue` domain which belongs to the [Hue integration](/integrations/hue)."
- topic: Entity
  description: "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 `%`)."
- topic: Event
  description: "An [event](/docs/configuration/events/) is when something happens."
- topic: Frontend
  description: "The [frontend](/integrations/frontend/) is a necessary component for the UI, it is also where you can define your themes."
- topic: Group
  description: "[Groups](/integrations/group/) are a way to organize your entities into a single unit."
- topic: HASS
  description: "HASS or [hass](/docs/tools/hass/) is often used as an abbreviation for Home Assistant. It is also the command-line tool."
- topic: HassOS
  description: "Another name for Home Assistant Operating System"  
- topic: Home Assistant Core
  description: 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.
- topic: Home Assistant Supervised (Previously Hass.io)
  description: "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."
- topic: Home Assistant Supervisor
  description: "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."
- topic: Home Assistant Operating System
  description: "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."
- topic: Integration
  description: "[Integrations](/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](/integrations/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."
- topic: Lovelace
  description: "Lovelace is the original code name of the UI that is now known as [Home Assistant dashboards](/dashboards)."
- topic: Light
  description: "A [light](/integrations/light) has a brightness you can control, and optionally color temperature or RGB color control."
- topic: Notification
  description: "You can use [notifications](/integrations/#notifications) to send messages, pictures, and more, to devices."
- topic: Packages
  description: "[Packages](/docs/configuration/packages/) allow you to bundle different component configurations together."
- topic: Platform
  description: "[Platforms](/docs/configuration/platform_options/) are building blocks provided by some integrations to be used by other integrations. For example, the [Light](/integrations/light) integration provides the `light platform` that is utilized by all integrations providing `light` entities such as e.g. [Hue](/integrations/hue)."
- topic: Scene
  description: "[Scenes](/integrations/scene/) 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."
- topic: Script
  description: "[Scripts](/docs/scripts/) are components that allow users to specify a sequence of actions to be executed by Home Assistant when turned on."
- topic: Sensor
  description: "[Sensors](/integrations/sensor) return information about a thing, for instance the level of water in a tank."
- topic: Selectors
  description: "[Selectors](/docs/blueprint/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."
- topic: Service
  description: "[Services](/docs/scripts/service-calls/) are called to perform actions."
- topic: Switch
  description: "[Switches](/integrations/switch) are things that have two states you can select between, such as turning on or off a socket."
- topic: Template
  description: "A [template](/docs/automation/templating/) is an automation definition that can include variables for the service or data from the trigger values. This allows automations to generate dynamic actions."
- topic: Trigger
  description: "A [trigger](/docs/automation/trigger/) is a set of values or conditions of a platform that are defined to cause an automation to run."
- topic: TTS
  description: "TTS ([text to speech](/integrations/tts)) allows Home Assistant to talk to you."
- topic: Variables
  description: "[Variables](/docs/scripts/#variables) are used to store values in memory that can be processed e.g. in a script."
- topic: Zone
  description: "[Zones](/integrations/zone/) are areas that can be used for presence detection."