This book presents a comprehensive treatment of the principles of hydraulics and pneumatics. The main objective of this book is to give a clear understanding of the concepts underlying hydraulics and pneumatics. Question papers of the last 12 years of VTU have been solved and a liberal number of numerical examples are given which include examination questions from various universities. Some of the problems of routine nature have been included to familiarize the readers with the numerical manipulations and orders of magnitude of various parameters that occur in the subject of hydraulics and pneumatics. This book is useful for students and engineers in mechanical, production, automobile, and mechatronics engineering who wish to understand hydraulics and pneumatics technology and apply it in solving the engineering problems and is primarily designed for the use of graduate and postgraduate students, as well as students who are preparing for AMIE.