Smart homeHubs & platforms · Lighting & switches · Sensors · Automation & scenes · Voice assistants & displays
Climate & airThermostats · Heat pumps · Air quality · Mini splits · Ventilation · Humidity control
Power & energyBackup power · EV charging · Energy monitoring · Solar & inverters · Generators
Security & accessSmart locks · Cameras & doorbells · Alarm systems · Garage & access
Water protectionLeak detection & shutoff · Water heaters · Sump monitoring
Networking & electricalHome networking · Smart panels · Structured wiring
Installation & interoperabilityWiring requirements · Professional installation · Maintenance & warranties
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Glossary

Home Systems terms, explained

Short, plain definitions of the words you'll see on product pages and spec sheets. Each one links to a guide when there's more to know.

C

C-wire
The common wire that gives a thermostat constant 24-volt power. Read the guide →
CADR
Clean air delivery rate, an AHAM rating of how much clean air a purifier delivers. Read the guide →

J

J1772
The standard Level 2 EV connector used by most non-Tesla EVs. Read the guide →

K

kWh
Kilowatt-hour, the unit of stored or used energy. Read the guide →

L

Line voltage
Thermostats that switch 120 or 240 volt heaters directly. Read the guide →

M

Matter
A shared smart-home standard that lets devices work across Apple, Google, Amazon and SmartThings. Read the guide →

N

NACS
The North American Charging Standard connector, standardized as SAE J3400. Read the guide →

O

O/B wire
The thermostat wire that switches a heat pump between heating and cooling. Read the guide →

T

Thread
A low-power mesh network used by many Matter devices. Read the guide →
Thread border router
A device that connects a Thread mesh to your home network. Read the guide →
Transfer switch
A device that safely connects backup power to home circuits. Read the guide →
True HEPA
A filter that captures at least 99.97 percent of particles at 0.3 microns. Read the guide →

Z

Z-Wave
A sub-gigahertz mesh network for smart-home devices that needs a hub. Read the guide →
Zigbee
A 2.4 GHz mesh network for smart-home devices that needs a hub. Read the guide →