Lighting Terms Explained

Glossary of Lighting Terms

As with most technical products, lighting comes with its own language and jargon which can sometimes be difficult to understand! At Pagazzi Lighting we want our customers to be able to shop for lighting with absolute confidence. If you often find yourself asking questions such as what are lumens? What's the difference between a bayonet and an Edison screw? What does LED mean? then look no further than this handy list of the most common lighting terms explained. These lighting definitions should clear up most of the common confusions, but we're here to help should you need any more information. If you have any questions, don't hesitate to get in touch and a member of our expert team will be more than happy to help. That's the Pagazzi Promise.

Accent Lighting

What is accent lighting? What is accent lighting used for? 
Accent lighting is simply directional lighting used to draw attention to a particular area or display object. This style of lighting can be used to accent anything from art or photographs to your television or special outdoor spaces!

Ambient Lighting

What does ambient lighting mean? Simply, the general lighting available in an environment. Includes daylight, but excludes accent and task lighting.


The process of lighting an object from behind. Popular for artwork and mirrors.


The end of the lamp that connects to the power socket.


A style of light bulb which makes use of pins which fit into grooves to lock the bulb in place. This is opposed to the most common screw style of bulb. For more information on bulb types, head over to our blog so you can shop for bulbs with confidence.


Light intensity measured in terms of distance from the fitting or source.

Compact Fluorescent Lamp (CFL)

A style of fluorescent lamp/bulb designed to replace traditional incandescent bulbs. CFLs emit the same amount of light as incandescents but use between a fifth and third of the electricity.

Colour Temperature

What is colour temperature? Colour temperature is the method of describing the appearance of light emitted by a bulb, and is typically expressed in units Kelvin. Visit our blog for more information on Colour Temperature and the Kelvin scale to ensure you buy the right bulb for the right purpose.

Cool White

The unofficial name given to the light produced at around 4100 Kelvin. When would you use cool white lighting? Cool white is recommended for use in high function rooms such as kitchens, studies, and bathrooms or in office/hospital environments to improve visibility.

Cost of Light

The cost of maintaining and operating a lighting layout. A term and concept most commonly applied in corporate or retail settings where the cost of light is high and needs to be carefully managed.


What is CRI? CRI is The International system used for measuring a light’s ability to render colour accurately. The scale runs from 0-100 and the higher the score the richer colours appear under the light being measured.

Daylight Harvesting

Building and lighting plans designed with the intention of making the best use of daylight in order to bring down power costs and help the environment.


What is a diffuser in lighting? A diffuser is any object which is used to spread and scatter light across an area, usually with the intention of softening the light to make it more calming and comforting.


Devices which alter the voltage waveform in order to lower the brightness of a light without entirely switching it off. Help to create ambience.


Lighting typically recessed into the ceiling, which cast light downward in a narrow beam.

Edison Screw

The most common style of light bulb with a threaded screw base. For more information on bulb types, head over to our blog so you can shop for bulbs with confidence.


A measurement of how effective a light is at converting energy into to lumens of visible light. See Lumens for more information.


The fraction or percentage of electrical energy converted into visible light.


The threadlike conductor within a traditional or vintage/decorative bulb which is heated to the point of incandescence by passing electricity. Learn more about our range of vintage bulbs and add a touch of retro to your interiors.


Finishing is done to improve the look, quality or properties of a product. Finishes range from copper to nickel to chrome and are largely aesthetic in lighting design.


Lighting mounted directly to the ceiling to conserve space. Where should you use flush lighting? Flush lights are recommended for rooms with low ceilings.


Discomfort or impaired visibility caused by excessively harsh or bright lighting.


What is illuminance? Illuminance is the level of light on a particular surface, typically measured in lux.

Indirect Lighting

The process of lighting a room by directing light upwards to bounce off the ceiling and diffuse soft light around the space.

IP Rating

What is an IP rating? The IP (Ingress Protection) Rating of a product is its level of protection against foreign materials. How does the IP rating work? The rating is represented by two numbers. The first digit is the protection rating against solid foreign objects (i.e. dust) and the second digit represents the protection against water. Purchasing the correctly rated product is especially important when purchasing lighting for your bathroom, as water and electricity can be a deadly combination. If you have any questions regarding the suitability of a product for your bathroom always consult an electrician or contact us by phone or email. We’ll be happy to help!


What does LED stand for? LED stand's for light-emitting diode and they are fast replacing previous types of lights due to their high levels of energy efficiency and efficacy.

Light Pollution

What is light pollution? Light pollution is simply excess light indirectly diffusing into areas where it is not required or wanted.


What are lumens? And how are lumens different to watts? Lumens are a better method of measurement for brightness and quality of light than watts. Watts is the measurement of power required to power bulb, whereas lumens are a measure of brightness. The higher the lumens, the brighter the light. For more information on Lumens, be sure to visit our handy guide!


Another word for fixture – an entire lamp comprised of all the relevant parts/decorative elements necessary for the finished product.


Sometimes referred to as a drop or suspended. A single fitting which hangs from the ceiling from a cord or chain. Decorative and often hung in groups.


A type of fitting which is hung directly onto a wall. Usually directing light upwards and will generally require an electrical box to prevent any hanging wires.


A fitting which fixes directly onto the ceiling and does not usually exceed more than 35cm in height – offering the option of a decorative ceiling light without the impracticalities of a grand chandelier. Recommended for rooms with low ceilings.


An independent cover for a lamp’s base. Used to cover the bulb and often acts as a diffuser and additional decorative element.


A fitting projecting a single narrow beam of light onto a person or object. Most commonly used as task or accent lighting.


A style of chandelier inspired by space-age satellites. Most recognisable by their decorative spheres radiating out from a central point.


A table or floor lamp which has a base made up of three legs.

Warm White

Refers to a colour temperature around 3000K, providing a yellowish-white light. Where should you use warm white? Warm white is recommended for living spaces where you want to create a relaxed and homely feel. 


What are watts? A measure of how much power it takes to illuminate a light bulb. Fast becoming obsolete having been replaced by the more suitable Lumens measurement.