This book deals with some basic thermodynamic and transport properties of fluids and solids that are of interest in engineering applications. Various notions about the basic structure of matter, fundamental concepts of our physical world and the conditions of equilibrium between different phases of matter are discussed in the first part of the book. The macroscopic properties of fluids and solids are explained in the latter part. The book is written for first-year university students in engineering. Therefore, simple derivations and clear explanations have been preferred to detailed theoretical treatment. Illustrative problems, spaced throughout the text, demonstrate the application of various concepts and facilitate a better understanding of the theory. The text provides a sound first treatment of many properties of fluids and solids of interest in all the engineering disciplines.