Explanations of Lighting Lingo | A Glossary of Terms

Photosensitive Mono and Polychromatic color render as it pertains to the kelvin scale is not exclusive to the atmospheric refraction cause and affect to our orbital photoreceptors. 

UM... WHAT?     

Below is a list of terms. We want you to be informed. 



Unit of Electrical Power Consumption.   A 100w light bulb is drawing 100 Watts of electricity every second it is lit. Wattage can also indicate the rate in which energy is generated, as well.  

 Watts do not indicate the brightness of a fixture. A 5w bulb could be brighter compared to a 10w bulb. Brightness is measured in Lumens 


Measure of Brightness or measure of perceived power of light.  An example to be able to relate this to something common, would be to understand that an incandescent 60w light bulb will typically generate 800 lumens. Most typical incandescent light bulbs inside the home were between 40w-60w, or 450-800 Lumens.  

Note - The Lumen replaced the measure of brightness called “Candela” in 2019. Candela was used as measurement compared to the brightness of a standard wax candela. One Candela equals roughly one Lumen. To better explain and simplify, If you were to shop for a flashlight and it was advertised as delivering 1000 candlepower, this would translate to 1000 Lumens.  However, Candle Power and Candela do not exactly translate as Candle Power is often measured using focused lighting and not overall emission of visible Light 


Electrical potential between two points, the potential for energy to move. An easier to understand way to define Voltage is to understand that Voltage is the pressure from a source to push electricity.  An analogy would be to think of Voltage as water when turning on a faucet.   


Strength of an electrical current.  


A measure of electrical resistance between two points.  An analogy would be water flowing though pipes, a smaller diameter pipe would flow less water/Ohms compared to a larger diameter pipe.  

Socket/Bulb Base

A bulb base is the part that screws in, pushes in, clips in, or otherwise is safely connected to a light fixture.  Numerous bases are used and a reference page could be seen here. 

Bulb Types

Below are types of Light Bulbs. The primary difference between bulbs is how light is produced.   

LED – Light Emitting Diode | 80 Lumens per Watt

  LED Light bulbs typically have far longer lifespan and use less energy at similar lumen output (brightness) compared to the common incandescent or CFL. Also, an LED bulb does not have to “warm up” to full brightness like CFLs typically need to achieve full brightness.  Another benefit is that LED lightbulbs typically radiate very low amounts of heat.  

CFL- Compact Fluorescent | 60 Lumens per Watt

 These are often the “curly” or “Twisted” bulbs. These work by sending an electrical current through a tube containing argon (gas) and a small amount of mercury vapor. This creates and excites a fluorescent coating, called phosphor, inside the tube which then emits light.  


Larger version of CFL bulbs. Often used in over head shop lights, retail, and office environments.  

  • Note about Fluorescent and CFL bulbs. These bulbs contain mercury which is toxic. Disposing of these light bulbs is typically regulated by local municipalities and have specific disposal rules. Often when purchased, the seller will also be responsible for disposal of fluorescent light bulbs from their customers.  

Incandescent  | 25 Lumens per Watt

The old common bulb. These are still available and fairly common.  These work by heating a tungsten filament with electricity until it glows within a glass globe containing an inert gas such as argon, thus giving off light... and heat. 

Halogen | 25 Lumens per Watt

These bulbs are very similar to incandescent in how they create light. The main difference is that these bulbs contain a halogen ; The name "halogen" means "salt-producing". When halogens react with metals, they produce a wide range of salts, including calcium fluoride, sodium chloride (common table salt), silver bromide and potassium iodide. This difference from a standard incandescent allows the filament to be hotter, thus, brighter. Typically Halogens will last longer compared to the common Incandescent bulb.

Metal Halide 

Typical used Stadiums, Construction sites, stages and concerts, and commercial exterior or interior warehouse lighting. Metal-halide lamps produce light by ionizing a mixture of gases in an electric arc. The primary color emitted from these lights are whiter compared to Sodium Halide bulbs. Though these bulbs are typically large, this technology is carried over to the automotive lighting industry as Xenon and/or High Intensity Discharge lights.  

Sodium Halide

Extremely similar to Metal Halide, but produces a amber/yellow color tone. Because of this, these bulbs of more often used in Street and Parking lot lighting. The warmer tone given off by these bulbs tends to be less obstructive, yet still bright, as related to illuminating a roadway for drivers.  

 Note - Although similar, Sodium Halide and Metal Halide are not interchangeable. They require different Ballasts. 


 A Ballast is used in fluorescent and halide bulbs to provide an electrical spike to generate the initial lighting of the elements, then it will regulate the power draw of the fixture to keep a consistent electrical flow. 


Used often in LED Lighting, a driver acts as an electrical restrictor to provide the correct amount of power to operate an LED fixture, or fixtures. This is used to take a typical 240V110W outlet in the home to a 12V or 24V output for LED Lighting 


Similar and often called a Driver, but typically used in low voltage and exterior lighting. This takes a typical 240V 110W outlet in the home down to a 12V or 24V output for Low Voltage Lighting

UL | ETL | CSA Certifications 

Various abbreviations will be found when purchasing lighting, plumbing, electronics, ladders, doors, appliances, and just about anything you, as a consumer, can use personally or professionally.  Some of the abbreviations indicate that the item in question passed a test for safety and accuracy of the ability of the item to be used for it's intended purpose without danger. Some abbreviations are used as a mark of conformity. For example, the UPC  - Uniform Plumbing Code, maintains that product sold in the U.S.A. needs to adhere to specific safety, longevity, size, durability, purpose, and more.

Regarding electrical items, such as lighting, bulbs, fuses, etc, OSHA created the Nationally Recognized Testing Laboratory Program.  According to OSHA.gov:

"Recognizes private sector organizations to perform certification for certain products to ensure that they meet the requirements of both the construction and general industry OSHA electrical standards. Each NRTL has a scope of test standards that they are recognized for, and each NRTL uses its own unique registered certification mark(s) to designate product conformance to the applicable product safety test standards. After certifying a product, the NRTL authorizes the manufacturer to apply a registered certification mark to the product. If the certification is done under the NRTL program, this mark signifies that the NRTL tested and certified the product, and that the product complies with the requirements of one or more appropriate product safety test standards."

Most Products on ShopforLights are certified. Some product, such as certain accessories are not required to hold certification. However, if the item uses electricity, it certainly will have a certification. 

Some Certifications are:


ETL  Intertek 

Commonly seen as cETLus and indicates that the product was tested and has met the certification requirements for the U.S.A and Canada. 

UL  Underwriters Laboratories 

Commonly seen as cULus and indicates that the product was tested and has met the certification requirements for the U.S.A and Canada. 

UL Listed Product badge

CSA Canadian Standards Association 

Commonly cCSAus Indicates that the product was tested and has met the certification requirements for the U.S.A and Canada

CSA Certified logo


CRI, Color Rendering Index 

Color Rendering Index is a measure of the ability of an artificial light source to show accuracy of the color of an object as it would be seen in natural light.  The range measures from 0 - 100. 0 would indicate that all color looks the same and someone would only seen in shades of gray. Conversely, an item seen with a light with a CRI of 100 would appear as it should in sunlight.  Interesting fact - Scuba divers essentially swim through the range of CRI. The deeper under water, the less light refraction, and thus, less visible color.   

Kelvin Temperature

   Often Kelvin Temperature is something that is overlooked when shopping for a lightbulb. From years of working in lighting stores, big box and small, I have seen the majority of light bulb shoppers look for a bulb based on Watts, Base Size, and Price.  What then happens is the shopper goes home, installs a light bulb, turns on the fixture, and they are surprised to find that all the color in the room has been changed. It's possible the paint color is suddenly something they dislike. Their food could look less appetizing, and they might even notice they have more difficulty reading. What happened?    It's possible they swung from one end of the Kelvin Scale to the other. 

The Kelvin Scale, in simple terms, is a range of numbers from 1000 to 10,000. The higher the number, the more "Blueish", or Cooler, the lighting and the lower the number, the more "Orange-ish", or Warmer the lighting.  This is very intertwined with the Color Rendering Index.  (Color Rendering is how close to natural sunlight a color is seen under a light) 

This scale is important when Shopping for Lights.  If your home has Red, Yellows, Browns, Tans, and Orange tones, lighting with a lower Kelvin number will maintain the contrast of these colors. Conversely, It can tend to lower the vibrancy of Blues, and make a Purple appear more bluish (Because the red is toned down) 

Generally Speaking, a fixture or bulb with a 3500k - 5500K will maintain color accuracy and enhance colors more equally.  Shopping online at at a store you will find a range typically from 2000K (Warmer) to 6500K (Cooler)