This book describes the state of the art across the broad range of spectroscopic techniques used in the study of biological systems. It reviews some of the latest advances achieved in the application of these techniques in the analysis and characterization of small and large biological compounds, covering topics such as VUV/UV and UV-visible spectroscopies, fluorescence spectroscopy, IR and Raman techniques, dynamic light scattering (DLS), circular dichroism (CD/SR-CD), pulsed electron paramagnetic resonance techniques, Mössbauer spectroscopy, nuclear magnetic resonance, X-ray methods and electron and ion impact spectroscopies. The second part of the book focuses on modelling methods and illustrates how these tools have been used and integrated with other experimental and theoretical techniques including also electron transfer processes and fast kinetics methods. The book will benefit students, researchers and professionals working with these techniques to understand the fundamental mechanisms of biological systems.