Infrared

Infrared (IR) emission is electromagnetic emission of a wavelength longer than that of noticeable light, but shorter than that of radio waves. The name means "below red", red being the color of detectable light of longest wavelength. Infrared radiation spans three instructions of magnitude and has wavelengths between about 750 nm and 1 mm.
These divisions are suitable by the different human response to this radiation: near infrared is the area closest in wavelength to the radiation detectable by the human eye, mid and far infrared are gradually further from the visible regime. Other definitions follow different physical mechanisms and the newest follow technical reasons .Unfortunately the international standards for these specifications are not currently obtainable.
The boundary between visible and infrared light is not precisely defined. The human eye is markedly less responsive to light above 700 nm wavelength, so longer frequencies make irrelevant contributions to scenes illuminated by common light sources. But particularly strong light (e.g., from lasers, or from bright daylight with the visible light removed by colored gels can be detected up to approximately 780 nm, and will be apparent as red light. The onset of infrared is defined at different values typically between 700 nm and 780 nm.