This textbook begins with a description of the Earth's plasma environment, followed by the derivation of single particle motions in electromagnetic fields, with applications to the Earth's magnetosphere. Also discussed are the origin and effects of collisions and conductivities, formation of the ionosphere, magnetospheric convection and dynamics, and solar wind-magnetosphere coupling.The second half of the book presents a more theoretical foundation of plasma physics, starting with kinetic theory. Introducing moments of distribution function permits the derivation of the fluid equations, followed by an analysis of fluid boundaries, with the Earth's magnetopause and bow shock as examples, and finally, fluid and kinetic theory are applied to derive the relevant wave modes in a plasma.This revised edition seamlessly integrates new sections on magnetopause reconstruction, as well as instability theory and thermal fluctuations based on new developments in space physics. Applications such as the important problems of collisionless reconnection and collisionless shocks are covered, and some problems have also been included at the end of each chapter.