This book reviews the stellar processes that generate the space environment at which exoplanets reside, and the planetary processes that interact with the space environment. It summarizes the last decade of research on this topic and explores how space physics processes may be important for the retention and chemical composition of the atmospheres of exoplanets. These are important factors for creating the conditions of exoplanetary habitability. This book is divided into three parts: the space environment, the planets, and star-planet interaction processes that are unique to exoplanetary systems. Part I describes the background stellar environment, going from general stellar evolution, to stellar activity, and then the creation of the space environment around exoplanets. Part II describes the impact of the space environment on the upper atmospheres of exoplanets. Finally, Part III focuses on unique star-planet interaction processes that are expected in close-in exoplanets, which are very different from what we find in our own solar system.