Smart Home Glossary 2026 — Every Term Explained

A

Alexa

Amazon's voice assistant. Lives in Echo devices. Controls smart home devices via voice. See: How to Set Up Alexa.

Automation

A rule that runs actions automatically without you asking. "When I leave home, turn off all lights" is an automation. See: Automations Guide.

B

B22

Bayonet Cap bulb fitting. Common in UK homes — push and twist to lock. Smart bulbs are available in B22 for UK compatibility.

Bridge / Hub

A device that connects smart home devices to your internet and to each other. The Philips Hue Bridge connects Hue bulbs to WiFi. See: Smart Hubs Guide.

Bluetooth

Short-range wireless protocol (up to ~10m). Used by some smart devices for direct phone connection without WiFi. Philips Hue uses Bluetooth as a backup to Zigbee.

C

C-wire (Common wire)

A thermostat wiring terminal that provides continuous power. Required by some smart thermostats (Amazon Smart Thermostat). Ecobee includes a Power Extender Kit to work without one.

Colour temperature

Measured in Kelvin (K). Lower = warmer/more orange (2700K like a traditional bulb). Higher = cooler/bluer (6500K like daylight). Tunable white bulbs let you adjust this.

D

Dimmer switch

A wall switch that reduces power to dim a light. Standard dimmers are incompatible with smart bulbs — they need constant power. Lutron Caseta is the exception.

DoorSense

August Lock's feature that detects whether your door is physically closed before allowing auto-lock. Prevents locking into an open door.

E

E27 / E26

Edison Screw bulb fitting. Screw-in. E27 is the European/UK size. E26 is the US size (slightly smaller). Most smart bulbs specify which they use.

E-E-A-T

Experience, Expertise, Authoritativeness, Trustworthiness — Google's framework for evaluating content quality. Not a smart home term but explains why our guides include testing methodology.

Ecosystem

A family of compatible smart home products and the platform that connects them. The three main ecosystems are Alexa, Google Home, and Apple HomeKit.

G

Geofencing

Using your phone's location to trigger automations. When your phone leaves your home area, "Away Mode" activates. When you return, heating turns on. Works in Alexa, Google Home, and HomeKit.

Google Home

Google's smart home platform. Uses Google Assistant voice commands. Works with Nest products natively. See: How to Set Up Google Home.

GU10

Spotlight bulb fitting common in UK kitchen downlighters. Push and quarter-turn to install. Smart GU10 bulbs are available from Philips Hue, LIFX, and others.

H

Home Assistant

Open-source smart home software that runs locally on your own hardware. No cloud, no subscriptions, maximum flexibility. See: Home Assistant Guide.

HomeKit

Apple's smart home platform. Runs automations locally on a hub (HomePod, Apple TV). More private than Alexa or Google. Requires iPhone for setup. See: How to Set Up HomeKit.

HomeKit Secure Video

Apple's camera standard. Footage is end-to-end encrypted and stored in your iCloud — Apple cannot see it. Logitech Circle View, Arlo, and Eufy support it.

Hub

See Bridge.

I

IP Rating

IP65, IP67 etc. Rates a device's resistance to dust and water. IP65 = protected against water jets (fine outdoors). IP67 = survives temporary immersion. Check this on outdoor cameras and smart plugs.

L

Local processing

When automations or commands are handled by a device in your home rather than cloud servers. Faster (no internet round-trip), works during internet outages, more private. HomeKit and Home Assistant are local-first.

Lumens

The actual measure of light brightness. A standard 60W incandescent = ~800 lumens. A 75W incandescent = ~1100 lumens. Check lumens when buying smart bulbs — wattage ratings are misleading for LEDs.

M

Matter

A new open standard allowing one device to work across all major platforms simultaneously. Matter 1.0 launched 2022; Matter 1.5 (Nov 2025) added camera support. Now covers the whole home. See: Matter Explained.

Mesh WiFi

A WiFi system using multiple nodes that work together. Eliminates dead zones and reduces congestion for smart home devices. See: Best Mesh WiFi Guide.

R

Routine

In Alexa: a sequence of automated actions triggered by voice, schedule, or event. Equivalent to automations in other platforms. See: Alexa Routines Guide.

S

Scene

A saved combination of device states activated with one command. "Movie Mode" = dim lights to 20%, lower blinds, turn on TV. Scenes are activated manually; automations run automatically.

Siri

Apple's voice assistant. Used to control HomeKit devices. Processes more requests on-device than Alexa or Google, making it more private.

Smart plug

A device that plugs into a standard wall outlet and adds smart control to whatever is plugged into it. No installation required. See: Best Smart Plugs Guide.

T

Thread

A mesh wireless protocol for smart home devices. Faster than WiFi, doesn't congest your network, excellent battery life for sensors. Requires a Thread Border Router. See: Protocol Guide.

Thread Border Router

A device that connects Thread devices to your network and internet. HomePod mini, Apple TV 4K, and Eero Pro 6E all include Thread border routers.

U

Uptime

The percentage of time a device is connected and responsive. 99.8% uptime = 1 disconnection per 500 commands. 91% = 1 per 11 commands. Our 30-day reliability study measured this for 8 smart bulbs. See: Reliability Study.

W

Works with Alexa / Works with Google

Certification labels indicating official integration with those platforms. More reliable than unofficial integrations. Look for these badges when buying.

Z

Zigbee

A low-power mesh wireless protocol used by Philips Hue, Ikea, and many sensors. Doesn't use your WiFi. Long battery life for sensors. Requires a Zigbee hub. See: Protocol Guide.

Z-Wave

A dedicated wireless protocol on a separate frequency (868/908MHz). Used in security devices and smart locks. More secure than WiFi, requires a Z-Wave hub.