Spectroscopy and spectrography are terms used to refer to the measurement of radiation intensity as a function of wavelength and are often used to describe experimental spectroscopic methods. Daily observations of colour can be related to spectroscopy. Spectroscopic studies were central to the development of quantum mechanics and included Max Planck’s explanation of blackbody radiation, Albert Einstein’s explanation of the photoelectric effect and Niels Bohr’s explanation of atomic structure and spectra. Spectroscopy is used in physical and analytical chemistry because atoms and molecules have unique spectra. The book explores the subject of Spectroscopy and offers a foundation of knowledge towards the same. Topics include – structure of solids, atomic theory, atomic orbitals, oxidation and reduction, spectroscopic reactions, etc.