LED stands for “light emitting diode.” A diode is an electrical component with two terminals which conduct the electricity only in one direction. With an electrical current, the diode emits a bright light around the small bulb. Compared to incandescent and CFL bulbs, LED lights are more efficient at turning energy into light.

Colour temperatures over 5000 K are called “cool colours” (bluish), while lower colour temperatures (2700–3000 K) are called “warm colours” (yellowish) Colour temperature refers to a characterization of the spectral properties of a light source and is commonly used during the production phase in the film and photography industries.

Low colour temperature is the warmer, more yellow to red light while high colour temperature is the colder, more blue light. Daylight, for example, has a lower colour temperature near dawn and a higher one during the day. The standard unit of measurement for colour temperature is Kelvin (K).

Some typical colour values include the following;
• Candles or oil lamps: 1000K
• Household light bulbs: 2500K
• Bright sunshine on a clear day: 6000K
• Very overcast sky: 10,000K

Constant Voltage LEDs make use of a resistor in order control power through the LED components. These systems require precise voltage throughout the circuit to provide even lighting. Constant voltage systems tend to be less consistent due to voltage drops or inconsistent forward voltage through the system.

Constant current LEDs are regulated and have an on-board driver to keep the current constant across the LEDs regardless of the voltage change. These are more reliable and provide more consistent brightness across the system. It is possible to have much longer chains of constant current LED whilst still maintaining even brightness across the chain.

A Watt is a measure of electricity used by a device. A watt is the measure of consumption or usage. It has absolutely nothing to do with light out. A Lumen is a measure of visible light from a light source. It is important to measure an LED’s efficacy(Lm/w)to determine how much light is emitted per watt of energy consumed. LEDs with higher efficacy will require fewer drivers (power supplies) for the same level of brightness.

IP (or “Ingress Protection”) ratings are used to define levels of sealing effectiveness of electrical enclosures against intrusion from foreign bodies (tools, dirt etc) and moisture. The numbers that follow the IP each have a specific meaning. The first indicates the degree of protection (of people) from moving parts, as well as the protection of enclosed equipment from foreign bodies. The second defines the protection level that the enclosure enjoys from various forms of moisture (drips, sprays, submersion etc).