Do you need to understand feedback? Perhaps you're a little rusty on theory basics? Dig in to this self-contained guide for an accessible and concise explanation of the fundamentals. Distills the relevant essence of linear system theory, calculus, differential equations, linear algebra, basic physics, numerical methods, and complex analysis, and links them back to an explanation of feedback theory. Provides a tight synthesis of analytical and conceptual understanding. Maintains a focus on common use cases. Whether you are a struggling undergraduate, a doctoral student preparing for your qualifying exams, or an industry practitioner, this easy-to-understand book invites you to relax, enjoy the material, and follow your curiosity.