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Lighting Glossary

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 confusion, 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.


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

Bar Pendant

A Bar pendant is a pendant arranged in a straight line. It usually features multiple lights fixed from a linear structure. Linear pendants work great for lighting over kitchen islands or a long dining table.

Bayonet (B22)

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.


Brass is a finish often used in lighting. Antique Brass whilst not made from brass often has a mellow colour to achieve a rustic look and it’s most often used in traditional homes. On the other hand, for a lamp to be solid brass it must be made purely from this alloy, from its core to its exterior. Pure brass can always be polished to its original shine. This material is highly durable and mostly used in high-end lighting and décor accessories.

Candlelight Bulb

A candlelight bulb as its name suggests is a bulb with the shape of a flame from a candle. This type of bulb has a decorative element to it that mimics the candle’s flames. E14 and E27 light bulbs are the most common for this shape. Works well in desk lamps, chandeliers, and wall lights for a vintage look.


Normally we use ceramics as table lamp bases with many different types of glazes. Ceramic lamps not only bring function but also a decorative touch. Typically to add a romantic, country, hand-made feeling to a room.


Chandeliers are pendant lights with multiple arms and sometimes layers of arms. Originally, when there was no electricity, chandeliers used candles to light up, nowadays most chandeliers are lit up using candlelight bulbs to imitate their origins. Once considered a luxury item to adorn the houses of the wealthy, are now available in a wide range of designs and budget-friendly prices to spruce up your home without breaking the bank.

CCT Correlated Colour Temperature

Lamp colour temperature is measured in Kelvins (K) and indicates how warm or cool a light appears to the human eye. The warmer the lamp the redder it is whilst the cooler the lamp the more blue is present. Before LEDs, old lamps used to be warm (over 2000K) and appeared redder to the naked eye. Whilst LED lamps come in a variety of temperatures, including daylight.

In general, the look and feel of a space can be greatly affected by colour temperature. The cooler the lamp the more energising the light will feel. On that, warm lamps create a cosy feel.

CRI or Colour Rendering Index

The Colour Rendering Index (CRI) is the measurement of how a light source shows objects in comparison to sunlight. The scale runs from 0-100 and the higher the score the more faithful colours appear under the light. The higher the value of CRI, the better the bulb’s colour rendition. Generally, a CRI of 80 or above is considered good.


A modern finish to any space, chrome lights spell a glamourous understated design to the room. This metallic shiny fixture, although modern, can work well in traditional spaces. The most common designs are polished chrome and brushed chrome. Typically, brushed chrome has a matt finish whereas polished chrome is more reflective.


Crystal fixtures have always been prized for the way light shines through the light fitting showing every colour in the spectrum which creates the sparkle and shine which is necessary to create a statement chandelier.


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 light without entirely switching it off. Simply put, it raises or lowers the brightness of electric bulbs. Dimmer switches can help reduce your bill since you’ll be using fewer watts when the lights are dimmed. In this line, your bulbs will also last longer since they won’t be working as hard whilst they are dimmed. And, finally, you will be able to control the feeling of any room. Dim the lights while you watch TV or turn them back on when you are having dinner.

Easy-fit pendant (non-electric pendant)

Easy Fits are light shades that attach to a pre-existing lighting batten or suspension without having to re-wire or need an electrician. Easy Fits are anything from a chandelier to a shade.

ES Edison Screw (E27, E14)

The Edison Screw refers to the bulb cap with a threaded screw base. Very common in the UK and Europe.


This refers to the cap size of the bulb. As the name clues in, it’s a 27 mm screw cap.


The E14 bulb has a smaller screw cap fitting (14 mm) and is more commonly used in wall lights and decorative table lamps.


The filament in a bulb is the wire conductor within a traditional or vintage/decorative bulb which is heated to the point of incandescence by passing electricity. Those bulbs are made to look like the original Edison bulb.


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.

Flush and semi-flush ceiling lights

Lighting mounted directly to the ceiling to conserve space. It is recommended for bathrooms and other rooms with lower ceilings. Newer constructions in the UK are being built an average of 40 cm. shorter than older constructions. These lights are ideal to take up less space in your room thus, maximising the space in your room. Semi-flush ceiling lights are equally suited to lower ceilings but are more decorative. Usually attached to a fixed arm and is not directly flushed to the ceiling.

GLS bulb (General Lighting Service)

This is a light bulb shape you will be most familiar with. It is mainly found in ES (E27) and BC light bulb caps.

Golf ball light bulb

This is a light bulb shape as the name suggests resembling a golf ball in size and shape. Can be found in both bayonet and Edison lamps.

IP Rating

An IP rating (Ingress Protection) of a product is its level of protection against foreign materials such as dust, moisture, liquids, and accidental contact.

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!


LED stands for light-emitting diode and they are fast replacing previous types of lights due to their high levels of energy efficiency and efficacy. LED lights are able to produce the same amount of light as a traditional bulb using less energy. Another added benefit of LED lights is that they last much longer.

Lamp Shade

Lamp shades are often made of fabrics such as cotton or a polyester mix, but they can also be found in metallic and glass finishes. The shade will act as a light diffuser so that the glare of the light bounces. Shades are typically found in ceiling lights, floor lamps and table lamps.


A lumen is a measure of light output, it determines how bright a light source is. As LED has become readily available lumens are a more accurate method of measurement for brightness and quality of light than watts. Where watts measure the actual power required to light a bulb, lumens measure its brightness level. The higher the lumens, the brighter the light.


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

Outdoor Lighting

Outdoor lighting includes a wide range of lighting types designed to illuminate outdoor areas, as given by the name. Outdoor lighting should be rated to at least IP43 but we recommend IP44 and IP65 where possible.

Pendant 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.

Portable Lamps

A technical term for table and floor lamps. This term is used in the lighting industry to describe lamps which can be unplugged and moved from one room to another.


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.

Smart Lighting

Smart Light Bulbs allow the user to control their lighting system with a remote device. Lighting can be scheduled to be turned on or off, minimizing unnecessary energy usage. Those lights are Wi-Fi enabled which allows for them to be controlled from any device such as Google Home, Alexa or a mobile phone from anywhere. Most smart bulbs are dimmable and allow for colour changes helping to create the right atmosphere in the room.


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.

Touch Lamps

Touch lamps operate when you touch them. They may be dimmable, allowing the brightness of the lamp to be adjusted by touches. Touch lamps are an elegant and modern addition since they don’t require a mains connection.

Wall Light

As the name suggests is a light mounted to the wall. Wall lighting greatly contributes to creating ambient light in any space. Also, to provide directional light, drawing attention to the bits you want people to see.

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.


A watt is a unit of power. It measures how much power it takes to illuminate a light bulb. It is fast becoming obsolete having been replaced by the more suitable Lumen’s measurement.

Check our FAQs page if you still need more information on bulbs or what lighting to choose depending on the room.

Or call us on 03442571908 or email us at – our customer service representatives are based in our Head Office in Glasgow & at the end of the phone to help you out.