Lighting plays a crucial role in enhancing any space's ambiance, functionality, and design. Understanding key lighting terms can help you make informed decisions when selecting the right products, whether for residential, commercial, or outdoor settings. Each component contributes to creating the desired effect and energy efficiency from LED technology to smart lighting systems. This comprehensive lighting glossary covers essential terms related to lighting, including LED lighting, directional lighting, and advanced lighting technologies, providing a valuable resource for anyone looking to navigate the world of lighting with confidence and clarity.
#A
Accent Lighting: Focused light that highlights specific objects or areas, often used in landscaping or architectural lighting.
Ambient Lighting: General lighting that provides overall illumination in a room or area.
Architectural Lighting: Lighting used to highlight architectural elements, often for decorative purposes.
#B
Beam Angle: The angle at which light is emitted from a light source. A wider beam angle lights up a broader area, while a narrow angle focuses the light.
Brightness: The intensity of light emitted from a source, measured in lumens.
Ballast: A device that regulates the electrical current to fluorescent and HID lamps, ensuring the light operates efficiently.
Bi-pin Base: A type of lamp base with two pins for electrical contact, commonly found in some LED, fluorescent, and halogen lights.
Bollard Light: Outdoor lighting fixtures used to light pathways, often cylindrical in shape.
Baffle: A component in a recessed light fixture that reduces glare by absorbing or redirecting light.
Beam Spread: The spread or width of the light beam emitted by a fixture, typically measured in degrees.
Binning: The process of grouping LEDs by color and brightness to ensure uniformity in multi-LED installations.
Bollard: A short, vertical outdoor lighting fixture often used to illuminate pathways, driveways, or garden areas.
Bounce Lighting: Lighting that is reflected off a surface, such as a ceiling or wall, to create softer, more diffused illumination.
Bug Rating (BUG): A system that evaluates outdoor lighting in terms of backlight, uplight, and glare to minimize light pollution.
#C
CCT (Correlated Color Temperature): A measure of the color appearance of light, expressed in Kelvins (K). Lower numbers (2700K-3000K) appear warmer, while higher numbers (5000K+) appear cooler.
CRI (Color Rendering Index): A scale from 0 to 100 that measures how accurately a light source reveals the colors of objects, compared to natural light.
Cool White: A light with a color temperature between 4000K and 5000K, offering a bright, clean light.
Candela: The unit of luminous intensity that measures the power emitted by a light source in a specific direction.
Chandelier: A decorative ceiling-mounted light fixture with multiple arms for holding bulbs or lights.
Cove Lighting: Indirect lighting installed in a ledge or recessed area, often used to provide ambient lighting along ceilings.
Color Consistency: The ability of a light source to maintain the same color temperature and appearance over time or across multiple units.
Ceiling Rose: The decorative element that covers the connection point where a pendant light is attached to the ceiling.
Chase Lighting: A lighting effect where multiple lights are arranged in a series and turned on and off in sequence, often used in decorative or sign lighting.
Color Temperature Shift: A change in the color temperature of light as it is dimmed or aged over time.
#D
Dimmable: A feature that allows the brightness of a light to be adjusted.
Directional Lighting: Lighting that is directed at a specific area or object, such as track lighting or spotlights.
Daylight: Light with a color temperature around 5000K-6500K, simulating natural daylight.
Diffuser: A material or cover that spreads light evenly, reducing harsh shadows and glare.
Diffuse Lighting: Soft lighting that spreads evenly, reducing shadows and glare, commonly used in ambient lighting designs.
Driver: A device that regulates the power supply to LED lights, ensuring they receive the correct current.
Downlight: A lighting fixture that directs light downward, typically used in recessed lighting applications.
Dual Circuit Track Lighting: A track lighting system that allows different sets of lights to be controlled independently from the same track.
#E
Efficacy: The efficiency of a light source, measured in lumens per watt (lm/W), indicating how much light is produced per unit of power.
Edge-Lit LED: A type of LED panel where the light is emitted from the edges and diffused across the panel, providing uniform lighting.
Edison Bulb: A decorative, vintage-style bulb with an exposed filament, often used in accent lighting or industrial design.
Emergency Lighting: Lighting that activates automatically during a power outage or emergency to provide illumination for safety.
#F
Floodlight: A broad-beamed, high-intensity artificial light, often used outdoors for security or landscape lighting.
Filament: A wire or thread inside a traditional incandescent bulb that glows and produces light when heated by electricity.
Fixture: The housing for a light source, which holds the bulb or LED in place.
Flush Mount: A ceiling light fixture that is mounted directly to the ceiling without any gap or extension, often used in rooms with lower ceilings.
Full Cutoff Lighting: Outdoor lighting fixtures designed to emit no light above the horizontal plane, reducing light pollution.
Flicker: The rapid variation in light output that may be perceptible to the human eye, often caused by voltage fluctuations or incompatible dimmers.
#G
Ganging: The process of combining multiple lighting controls, such as switches or dimmers, into a single unit or wall plate to manage multiple light sources.
Gimbal Ring: A type of adjustable lighting fixture that allows the light source to be tilted and rotated to direct light where it's needed. Often used in recessed or track lighting for flexibility in beam direction.
Glare: Excessive brightness from a light source that causes discomfort or reduced visibility.
Glare Control: A feature or accessory in lighting design that reduces excessive brightness or direct exposure to the light source, often using baffles, louvers, or diffusers.
Grid Ceiling: A type of suspended ceiling that uses a grid structure to hold lighting fixtures such as troffers or panel lights. Commonly found in commercial spaces.
Grounded Lighting: A safety feature in electrical lighting that includes a ground wire to prevent electrical shock in case of a fault, especially in outdoor or wet area lighting installations.
Globe Light: A round or spherical lighting fixture, often used in decorative settings or pendant lighting, available in various sizes and styles.
Ghosting: A visual effect where faint outlines or shadows are visible due to improper light distribution or reflections from nearby surfaces.
Guard: A protective cage or cover used around outdoor or industrial light fixtures to prevent damage from impact or harsh environmental conditions.
Gobo: A template or stencil used in lighting to create patterns, shapes, or logos when light is projected onto a surface.
Glowing Bulb Effect: A lighting style where the bulb itself emits a soft glow, creating an ambient effect.
#H
Halogen: A type of incandescent lamp that contains halogen gas, allowing the bulb to burn hotter and more efficiently than standard incandescent bulbs, often producing brighter light.
Hardwired Lighting: A lighting fixture that is directly connected to a building's electrical wiring, requiring professional installation and providing a permanent lighting solution.
Heat Dissipation: The process by which a lighting fixture, particularly LEDs, releases heat to maintain optimal performance and prevent overheating. Heat sinks are often used for this purpose.
High Bay Lighting: Fixtures designed for ceilings that are 20 feet or higher, typically used in warehouses, gyms, and industrial spaces to provide ample illumination over large areas.
HID (High-Intensity Discharge): A type of lighting that produces light by creating an electric arc between two electrodes, commonly used in outdoor, stadium, and street lighting.
Honeycomb Louver: A grid-like accessory for lighting fixtures that reduces glare and focuses the light output, often used in directional lighting like spotlights or track lights.
Housing: The main body or frame of a light fixture that holds the electrical components and lamp or LED, often referring to recessed lighting or downlights.
Hue: The specific color or shade of light emitted by a light source, often referring to RGB or tunable lighting where the color can be adjusted.
Hardscape Lighting: Lighting specifically designed to be used in non-plant outdoor environments like pathways, walls, or patios, often using low-voltage systems for safety.
High Output (HO): Refers to lighting fixtures or bulbs that produce a higher level of brightness or lumens than standard versions, commonly found in commercial and industrial lighting.
Halogen Lamp: A type of incandescent lamp that uses halogen gas to increase efficiency and brightness compared to regular incandescent bulbs.
High Bay Lighting: Lighting used for spaces with high ceilings, typically over 20 feet, such as in warehouses or industrial buildings.
HID (High-Intensity Discharge) Lamp: A type of lamp that produces light by an electric arc between tungsten electrodes inside a gas-filled tube, used in street lighting and stadiums.
Hardscape Lighting: Outdoor lighting specifically designed for non-plant surfaces, such as patios, decks, and retaining walls.
Heat Sink: A component used in LED fixtures to dissipate heat, ensuring that the LED operates efficiently and has a long lifespan.
#I
IP Rating (Ingress Protection): A rating that indicates the level of protection provided by an enclosure against solids and liquids, important for outdoor lighting fixtures.
Indirect Lighting: Lighting that reflects off surfaces, such as walls or ceilings, to produce a soft and diffuse illumination.
In-ground Lighting: Light fixtures installed directly into the ground, often used for landscape lighting to highlight paths, trees, or architectural features.
#J
Junction Box: An enclosure that houses electrical connections, providing a safe place for wiring connections in lighting installations. It is often used when installing ceiling lights, wall sconces, or other fixtures.
J-Type Bulb: A linear halogen bulb with a double-ended design, commonly used in work lights, security lights, and some floodlight fixtures. The "J" refers to the shape and base type of the bulb.
#K
Kelvin (K): A unit of measurement used to define the color temperature of a light source.
LED (Light Emitting Diode): A semiconductor light source that emits light when an electric current passes through it. LEDs are energy-efficient and have a long lifespan.
Light Output: The total amount of visible light emitted by a light source, measured in lumens.
Lumen: A unit of measurement for light output or brightness.
#L
Lamp Life: The average number of hours a lamp or bulb is expected to last before failing or reaching a significant reduction in brightness.
Linear Lighting: Lighting fixtures that provide long, continuous lines of light, commonly used in commercial or architectural settings.
Load Factor: A measure of how efficiently a lighting system operates in relation to its full power capacity.
Louver: A structure with angled slats or fins used to control the direction of light, reducing glare or direct light.
Light Pollution: Excessive or misdirected artificial light that disrupts natural darkness and can affect ecosystems or visibility of stars in the night sky.
Lux: A unit of measurement for illuminance, representing the amount of light that falls on a surface.
#M
Motion Sensor Lighting: Lights that are activated when motion is detected, often used in outdoor security lighting.
Monochromatic Light: Light that consists of a single wavelength or color, often used in specialized lighting applications.
Micro-LED: A small, efficient type of LED used for fine-detail lighting applications, such as displays and signage.
Magnetic Ballast: A type of ballast used in fluorescent and HID lighting to regulate current. It operates using a coil of wire and a magnetic field, though it has largely been replaced by more efficient electronic ballasts.
Metal Halide Lamp: A type of high-intensity discharge (HID) lamp that produces light by passing electricity through a mixture of metal halides and mercury vapor. It is commonly used in large outdoor areas, such as sports fields or parking lots.
#N
Nano Lighting: Ultra-small light fixtures or LEDs used for precision lighting in architectural designs or small spaces.
Nanometer (nm): A unit of measurement used to describe the wavelength of light. Different wavelengths correspond to different colors in the visible light spectrum (e.g., blue light is around 450 nm, while red light is around 700 nm).
Neutral White: A type of light color with a color temperature typically between 3500K and 4000K. It produces a more balanced, natural light compared to warm white or cool white, and is often used in task lighting.
#O
OLED (Organic LED): A type of LED that uses organic compounds to emit light, known for being ultra-thin and flexible, often used in display technologies.
Optical Control: The process of shaping or directing light using reflectors, lenses, or diffusers to achieve the desired illumination pattern, such as focusing or spreading the light beam.
Overhead Lighting: Lighting that is mounted or recessed in the ceiling, providing general illumination for a space. It is often used in offices, kitchens, and large rooms.
#P
Photocell: A sensor that turns lights on or off based on ambient light levels, typically used in outdoor lighting systems.
Pendant Light: A light fixture suspended from the ceiling by a cord, chain, or metal rod, often used for task or accent lighting.
Parabolic Reflector (PAR): A type of lighting that uses a parabolic-shaped reflector to focus light in a particular direction, commonly used in stage lighting and spotlights.
Plinth Light: Small, low-level lights used to highlight architectural features like staircases or baseboards.
Power Factor: A measure of how effectively electrical power is converted into usable light by a lighting fixture.
Pendant Mount: A type of lighting fixture that hangs from the ceiling by a rod or chain, commonly used for task lighting or over dining areas.
Photometric Plan: A lighting design layout that shows how light is distributed across a space, often used in architectural and outdoor lighting planning.
Power Over Ethernet (PoE) Lighting: A lighting system that uses Ethernet cables to deliver both data and power, commonly found in smart buildings.
#Q
Quantum Dot Lighting: A type of lighting that uses quantum dot technology to produce highly accurate and vivid colors, commonly used in advanced displays and lighting applications.
Quick-connect Fixture: A lighting fixture that can be easily installed or removed without the need for complex wiring, often used in modular or temporary lighting setups.
Quartz Lamp: A type of halogen lamp where the envelope is made from quartz, which can withstand higher temperatures and provides brighter, more efficient lighting.
Quenching: The process of reducing or stopping an electrical discharge in lighting systems, particularly in gas-discharge lamps, to prevent overheating or damage.
Q-Track Lighting: A specific form of track lighting system known for its versatility and ease of installation, commonly used in residential and commercial applications where adjustable lighting is needed.
#R
Recessed Lighting: Lighting fixtures that are installed into a ceiling, creating a flush appearance.
RGB Lighting: LED lighting that can change colors by mixing red, green, and blue light.
Reflector Lamp: A light bulb designed with a reflective coating to direct light in a specific direction, often used in floodlights and spotlights.
Retrofitting: The process of replacing existing lighting systems with more energy-efficient alternatives, such as upgrading from incandescent to LED.
Reflectance: The measure of how much light is reflected from a surface, affecting the brightness of an area.
Retrofit Kit: A set of components used to upgrade existing light fixtures with more efficient technologies, such as LEDs, without replacing the entire fixture.
Rope Light: A flexible tube containing small bulbs or LEDs, commonly used for decorative or accent lighting.
#S
Spotlight: A type of directional lighting that focuses on a specific point or object.
Smart Lighting: Lighting that can be controlled via smartphones or smart home systems, often allowing for automation, dimming, and color changes.
Sconce: A wall-mounted light fixture used for accent or ambient lighting.
Step Light: Small, low-wattage lights installed along stairways for safety and decorative purposes.
Solar Lighting: Lighting that is powered by energy collected from sunlight, commonly used in outdoor applications like garden and pathway lighting.
Silhouette Lighting: Lighting that highlights the outline or shape of an object, creating a dramatic shadow effect.
Solar Panel: A device used to convert sunlight into electricity, commonly used to power solar-powered outdoor lighting.
Step-down Transformer: A device that reduces voltage from a higher level to a lower level, often used in low-voltage lighting systems.
#T
Task Lighting: Lighting that provides focused illumination for specific tasks, such as reading or cooking.
Track Lighting: A type of directional lighting where fixtures are mounted on a track, allowing them to be repositioned along the track.
Troffer Light: A rectangular or square lighting fixture that fits into a grid ceiling, commonly used in offices and commercial spaces.
Thermal Management: The process of controlling heat generated by lighting fixtures, especially important for LEDs to extend their lifespan.
Three-way Bulb: A type of bulb that has three brightness settings, commonly used in table lamps with compatible sockets.
Tunable White LED: An LED lighting system that allows the user to adjust the color temperature of the light output, from warm to cool white.
Task-specific Lighting: Lighting designed to illuminate specific tasks or areas, such as under-cabinet lights in kitchens or reading lamps.
#U
Under-cabinet Lighting: Lighting installed under kitchen cabinets to provide illumination for countertops and workspaces.
Uplighting: Lighting that is directed upward, often used to highlight walls, artwork, or landscape features.
#V
Volt: A unit of electrical potential, measuring the force needed to drive an electrical current through a circuit.
Voltage: The electrical potential difference between two points, often specified for lighting systems (e.g., low voltage for garden lighting).
Voltage Drop: The reduction in voltage that occurs when electricity travels a long distance through a wire, affecting the performance of low-voltage lighting systems.
#W
Watt: A unit of electrical power consumption, used to measure how much energy a lighting fixture uses.
Wattage: A measure of electrical power, indicating how much energy a light source consumes.
Warm White: A light with a color temperature between 2700K and 3000K, providing a warm, yellowish glow.
Wall Washer: A light fixture that spreads light over a wide, flat surface like a wall, creating an even glow.
Timer Lighting: Lights that can be programmed to turn on or off at specific times, often used for energy savings and security.
#X
Xenon Lamp: A type of gas-discharge lamp that produces bright, white light by passing electricity through xenon gas, commonly used in automotive headlights and some specialty lighting applications.
X-Ray Lighting: Lighting used in medical or industrial settings to assist with the visibility of X-ray processes, often requiring specialized shielding and precision.
X-Factor: A term sometimes used in lighting design to refer to the overall impact or special quality of lighting in a space, particularly in how it enhances aesthetic or mood.
#Y
Yoke: A bracket or frame used to mount or support lighting fixtures, especially in stage or studio lighting, allowing for adjustable positioning.
Yield: In lighting terms, yield refers to the amount of usable light or lumens produced by a light source relative to its energy consumption, often used in efficiency discussions.
Yellowing: The discoloration that can occur in certain types of lighting, such as fluorescent bulbs or plastic covers, where exposure to heat or UV light causes the material to turn yellow over time.
#Z
Zonal Lighting: Lighting that targets specific areas or zones within a space, such as task lighting in a kitchen or study area.
Zigbee Lighting: A wireless technology used in smart lighting systems that allows devices to communicate and control lighting remotely, commonly found in home automation systems.
Zero-Cross Dimming: A dimming technique that adjusts the power delivered to a light fixture when the electrical current crosses the zero point in its AC waveform, providing smooth dimming without flicker.