The Essential provides a concise overview of central concepts and terminology that frequently arise in the context of systemic coaching. The explanations are based on an approach rooted in interdisciplinary system theory, known as "person-centered system theory." The concepts and principles developed there enable a system-theoretically grounded and consistent understanding of the emergence, stability, and change of problem structures. This allows for central aspects and questions that arise in the field of coaching to be viewed from a system-theoretical perspective, facilitating the consistent further development and deepening of the action potential in systemic coaching.