This book provides a comprehensive and wide-ranging introduction to the fundamental principles of mechanical engineering in a distinct and clear manner. The book is intended for a core introductory course in the area of foundations and applications of mechanical engineering, prescribed for the first-year students of all disciplines of engineering. The book develops an intuitive understanding of the basic principles of machines and mechanisms in the areas of manufacturing processes, prime movers and thermal engineering. Numerous illustrative examples are provided to fortify these concepts throughout. The book provides the students a feel for applications of fundamental principles of mechanical engineering in the areas of steam boilers, internal combustion engines, refrigeration and air conditioning, and to devices such as turbines, pumps and robotics. No book on basic mechanical engineering is complete without an introduction to materials science. The text covers the treatment of the common engineering materials, highlighting their properties and applications. The text features several fully worked-out examples and numerical problems with answers for the relevant topics, large number of end-of-chapter review questions and multiple choice questions, which all enhance the value of the text to the students. This book is prescribed in Visvesvaraya Technological University.