This book provides an introduction of the general concepts behind NMR and its applications, including how to perform adequate NMR experiments and interpret data collected in liquids and solids to characterize molecule systems in terms of their structure and dynamics. It covers he theoretical basis of NMR spectroscopy, the theory of NMR relaxation, and the practice of relaxation measurements. NMR spectroscopy and relaxation studies in solutions and general principles and strategies involved in solid state NMR studies are also discussed. The book is ideal for scientists new to NMR, students, and investigators working in the areas of chemistry, biochemistry, biology, pharmaceutical sciences, or materials science.