Visible light
The electromagnetic spectrum is the range of frequencies of electromagnetic radiation and their respective wavelengths and photon energies. It ranges from frequencies below 1 Hz to frequencies above 1025 Hz, corresponding to wavelengths from 100 Mm to 1 pm[1]. Light is a part of the electromagnetic radiation spectrum and is only visible to humans when its wavelength ranges from approximately 400 nm (violet) to 700 nm (red). Different wavelengths of light will produce different visible colours[2].