Beginning at an introductory level, this text presents a thorough treatment of plasma physics, including an extensive discussion of its applications in thermonuclear fusion research. A novel feature of this book is its comprehensive description of the various concepts and formulas widely used in fusion theory based on the fundamental equations of the plasma fluid. The physics of fusion plasmas is explained mainly in relation to recent progress in tokamak research, but other plasma confinement schemes, such as stellarators and inertial confinement, are also described. The unique and systematic presentation will help readers to understand the overall structure of plasma theory and will facilitate access to more advanced literature on special topics.