Effect. Unit: Watt (W) Measurement of continuous power consumption. The effect does not indicate how much light is produced.
Energy. Unit: Kilowatt hours (kWh) Power we use during a specific time. Light source of 100W = 0,1KW.
Luminous flux. Unit: Lumen (lm) All light as a light source continuously generates in all directions. By comparison, one candle has about 12 lumens, 40W bulb about 420 lumens, and fluorescent lamps 39W about 3500 lumens.
Luminous efficiency. Unit: Lumen per watt (lm / W) Efficiency on a light source, generation of light / consumed watt. The light source is a transformer that converts electricity into light, the light range indicates the efficiency of light source. Thus, it is a measure of how the economic light source is. One should aim to get as many lumens as possible and consume as few watts as possible without sacrificing light quality.
Luminous intensity Unit: Candela (cd) The light flow in a given direction. Knowing candela, you can calculate the light that will reach a certain surface.
Illuminance. Unit: Lux (lx) The light flow that hits a surface. Lighting strength is the most common measure of light and easiest measurement. Lux can also be written as lumen per square meter, ie. light source light flow reaching a specific illuminated surface. For indoor work, the strength of 500 to 1000 lux is common, in home environment about 200lux.
Luminance. Unit: Candela per square meter (cd / m2) The perceived perception of the light on a surface. An indoor work space can have 150 candela per square meter, while a lighted road often has no more than 1-2 candela per square meter. The luminance can be measured but note that the luminance sensor is color blind and does not take into account the color properties of the surface.
Color temperature. Unit: Kelvin (K) Indicates the character of the light, eg Warm white, white or daylight. A low-color temperature means a hot-tinted incandescent light. The daylight is at 6500K which is a neutral balance between the colors in the light.