The nature of interaction between matter and electromagnetic radiation can be understood with the technique of spectroscopy. It is an exploratory tool used in the fields of astronomy, physics and chemistry to study the composition, electronic structure and physical structure of matter at the atomic and molecular scales, even over astronomical distances. Spectroscopy can be studied with variations in the type of radiative energy used to interact with matter, the nature of the interaction and the type of material used. Depending on these interactions, spectroscopy can be of different types, such as microwave spectroscopy, infrared spectroscopy, electron spectroscopy, absorption spectroscopy, emission spectroscopy, atomic spectroscopy, molecular spectroscopy, etc. It may be used for varied purposes, such as measuring toxic compounds in blood or different compounds in food, exploring electronic structures and conducting elemental analysis, etc. Spectrometers, spectral analyzers and spectrophotometers are some common devices used to achieve spectral measurement. This book unravels the recent studies in spectroscopy. Also included in this book is a detailed explanation of the various techniques and applications of this field. For all those who are interested in this technology, this book can prove to be an essential guide.