Accent Lighting
Directional lighting to emphasize a particular object or draw attention to a display item. .


Active Cooling
A cooling process that uses power for cooling components such as fans to actively exhaust heat from components.


The unit of measuring the rate of flow of electrical current: Current (Amps) = Power (Watts) / Voltage (Volts).


American Society of Heating, Refrigerating and Air-Conditioning Engineers.



The grouping of LEDs (from production) according to specifications, such as light output, color, and voltage so that LEDs of similar light performance are grouped.



A term used for the board or “light engine” to which the LEDs are applied. The chip or “light engine” is a circuitry board for the LED.


The quality of a color as determined by its dominant wavelength and its purity.


Color Definition
The color of uniformly illuminated objects described using three terms:
Hue: Describes the situation when the appearance of different colors is similar.
Lightness: Describes a range of grayness between black and white.
Chroma: Describes the degree of departure from gray of the same lightness and increasing color (e.g. red and redder).


Color Rendering Index (CRI)
A measurement of the ability of a light source to reproduce the colors of various objects in comparison to natural light.


Color Shift
The term used when lamps or LEDs change color over the lifespan. Color shift is greatly increased by poor heat dissipation.


Cool White
Bright light that is slightly blue in color, generally greater than 4,500K.


Correlated Color Temperature (CCT)
The numerical value of the color of a light source, measured in Kelvins. Red, warm colors are associated with lower color temperatures while blue, cool colors correspond with higher temperatures. Incandescent lamps are typically 3000K while fluorescent lamps range from 3000K – 7500K or higher.



Daylight Harvesting
Lighting design for building interiors that makes use of daylight as a way of reducing energy consumption.


Chip. The light emitting semiconductor.


Whether or not the lamp lumens can be varied while maintaining reliability.


A standard for digital communication networks that are commonly used for theatrical or stage lighting. A single DMX universe has 512 addressable channels.



The light output of a light source divided by the total electrical power input to that source, measured in lumens per watt.



A unit of illumination, equivalent to the amount of light produced one foot away from a candle and equal to one lumen per square foot.


Fully Rated Life
The end of the life of an LED is determined by the point at which the LED fails to deliver at least 70% of initial lumen output. LEDs are commonly marketed as having 50,000 hours of fully-rated lives.



Heat Sink
An object that conducts or convects heat away from an LED lamp.



The intensity of light falling on a surface area. If the area is measured in square feet, the unit of illuminance is footcandles, while if the area is measured in square meters, the unit of illuminance is lux.



Kelvin Temperature (K)
Term used to measure the comparative color appearance of a light source when compared to absolute black.



A Light Emitting Diode is a solid state lighting device that converts electrical energy directly into light. The semiconductor is composed of a p-region which carries positive electrical charges and an n-region which contains negative electrical charges. When the LED is turned on the electrons flow from the n-region to the p-region releasing energy that produces photons.


LED Array
An arrangement of LEDs onto a printed circuit board or other surface that is capable of producing light when powered.


LED Driver
An electronic circuit that converts input power into a current source which remains constant despite fluctuations in voltage. Read more about our Trinity line of LED remote power drivers.


Line-Voltage LED
Complete luminaires designed specifically for LED and are using line-voltage wiring to each luminaire, transforming power down at every fixture.


Low-Voltage LED
LED that uses low-voltage power distribution to each luminaire. The power conversion, drivers, control, and surge protection is done in a remote, accessible location. Learn about how you can save with low-voltage LED from LumaStream.


Lumen (lm)
Unit of measurement for the total amount of visible light emitted from a source, essentially a measure of brightness. The higher the lumen, the brighter the light.


Lumen Depreciation
Describes the percentage of light lost relative to the initial lumen output.


Lumen Maintenance
Compares the amount of light produced from a light source or from a luminaire when it is brand new to the amount of light output at a specific time in the future.


Lumens per Watt (LPW)
The ratio of light produced by an LED device, measured in lumens, divided by the power, measured in watts, required to operate the device used to measure LED performance.


Complete lighting unit, consisting of one or more of the following compoenents; lamps and lamp sockets, ballast(s), reflective material (lenses, refractors, louvers, blades, or other shielding). Socket hold the lamp in place and protect it, wiring connects the light to its power source, and reflective materials helps direct and distribute the light in the space. Efficient luminaires optimize the performance of each of its components.


Luminous Flux
Measure, usually given in lumens, of the total amount of visible light.


Lux (lx)
The international unit of illuminance, typically measured in lumens per square meter.


LED testing that measures total luminous flux, luminous intensity of distribution, electrical power, efficacy, and color characteristics.


LED testing that measures the lifespan of LEDS by measuring the amount of lumen depreciation.



Occupancy Sensor
Control device that turn lights off after the space becomes unoccupied.



Passive Cooling
A method of cooling that takes place without the use of power.



Radiant Flux
Measure of the total power of electromagnetic radiation.


Recessed Downlight
A small light fixture recessed into the ceiling that usually concentrates the light in a downward direction. See our recessed downlights.


The retrofit LED is a bulb or trim that is designed to convert an existing line voltage luminaire housing to an energy efficient LED luminaire.



Solid-State Lighting (SSL)
Lighting that uses LEDs to emit light from a solid object -a semiconductor- rather than from vacuums or gas tubes used in incandescent and fluorescent lighting. Solid-State Lighting does not contain moving parts that can break or shatter, potentially contaminating the environment.



Useful Life
The amount of light a lighting fixture delivers in an application, minus any wasted light.



A measurement of the electrical potential difference between oppositely charged conductors.



Warm White
Traditionally yellow color light similar to conventional bulbs, generally around 2,700K-3,500K.


Unit of measurement for the rate of energy conversion or transfer: Power (Watts) = Current (Amps) X Voltage (Volts).