Someone else already gave you the answer, but I think this is a better link https://en.m.wikipedia.org/wiki/Spectroscopy https://en.m.wikipedia.org/wiki/Spectro

Someone else already gave you the answer, but I think this is a better link https://en.m.wikipedia.org/wiki/Spectroscopy https://en.m.wikipedia.org/wiki/Spectroscopy > Spectroscopy is a branch of science concerned with the spectra of electromagnetic radiation as a function of its wavelength or frequency measured by spectrographic equipment, and other techniques, in order to obtain information concerning the structure and properties of matter