Wavelength: the color intensity of light changes, is can be described by data, this kind of data is called wavelength.The wavelengths of light we can see range from 380 to 780nm.Unit: nanometer (nm) Luminance: luminance refers to the degree of brightness of an object, defined as the luminous intensity per unit area.Unit: nit Light intensity: the brightness of a light source.That is, the physical quantity indicating the intensity of visible light radiation emitted by the light source in a certain direction and range.Unit: candlelight (CD) Flux: the sum of the amount of visible light emitted by a light source per second.Unit: lumen (Lm) Luminous efficiency: the flux of light emitted by the source divided by the power of the source.It is an important index to measure the energy saving of light source.Unit: lumens per watt (Lm/w). Color rendering: the degree to which an object is rendered by a light source.This is often called the “color rendering index” unit :Ra.Color temperature: the color of light emitted by the light source is the same as the color of light radiated by the black body at a certain temperature. The temperature of the black body is called the color temperature of the light source.Unit: kelvin of k.Glare: the visual discomfort caused by extremely bright objects or strong brightness contrast in the field of vision is called glare. Glare is an important factor affecting lighting quality.Synchronicity: two or more LED lights can run normally according to the way set by the program within the specified time, generally refers to the LED lights in the internal control mode, synchronicity is the basic requirement for LED lights to realize coordinated changes.Protection grade: IP protection level is the lamps and lanterns is according the characteristic of the dust, prevent moisture to classification, composed of two Numbers, the first number represents the level of dust, prevent the outside shooting of lamps and lanterns (0-6), the second number represents moisture proof, waterproof lamps and lanterns of shooting the sealing degree (0 to 8), the greater the number said the higher degree of protection.