This new resource provides a comprehensive and concise introduction of the underpinnings and fundamentals of electrical circuits. Models, the limitations of models, and examples are clearly explained. The book examines circuits with static sources and explains how to reduce any circuit to a system of linear equations. Moreover, the book presents dynamic sources that exhibit transient phenomena that require the solution of linear differential equations. MATLAB code is used throughout the book to help solve key problems and assist engineers in the field. Additionally, this hands-on volume explores circuits with sinusoidal sources also known as the AC paradigm. The book provides another key mathematical tool known as a phasor which are mathematical objects based on complex number theory. The book emphasizes solutions for computing power, interpreting power and energy, and compensating electrical systems if the power factor is too low. Professionals are offered design guidance throughout the book with many real-world examples.