The book presents the conceptual foundations of modern avionics systems. Specifically, it contains a discussion of the principles underlying the prominent devices, circuits, sensors and subsystems used in avionics, complemented by an overview of the avionics design and certification processes. Following the discussion of foundational principles the book also presents the state of the art in civilian and military avionics, and concludes with a preview of the imminent advances in avionics. The book is concise, yet considerably comprehensive.