Saliva is very much essential for healthy oral cavity and better digestion of food. Knowledge about saliva is required in the field of medicine, forensic medicine and more importantly in the field of dentistry. Role of saliva is learnt under numerous aspects and it is very difficult to find entire aspects of saliva in one single study material in the literature. Hence, we aimed to put forth majority of facets of salivary glands and saliva which includes components, functions, types, physiology, flow of saliva, saliva as diagnostic tool and relation of saliva in health and diseases in our book.