This book serves as an introduction to boundary plasma physics, providing an accessible entry point to the topic of plasma exhaust in magnetic confinement devices. While it delivers a concise, rigorous, and comprehensive account of all the major scientific topics relevant to those working on the subject, it also remains accessible and easy to consult due to its modular and compact structure. Beginning with the basic kinetic and fluid descriptions of plasma, and advancing through plasma-surface interactions, filamentary transport and plasma detachment, to conclude with a discussion of divertor configurations, this book represents a necessary and timely addition to the literature on the fast-growing field of boundary plasma physics. It will appeal to experienced theoreticians or experimentalists looking to enter the field as well as graduate students wishing to learn about it.