This book begins where DC Theory leaves off, building on that foundation of learning the fundamentals. Beginning with a review of the methods and techniques of DC theory, this book adds the concepts of capacitance and inductance as they relate to alternating current (AC) theory and features a host of circuit analysis tools that will build on concepts already learned. An introduction to vectors and complex numbers is followed by an immersion into AC concepts as they compare to DC theory. Polyphase circuits, AC and DC generators, and inductance and capacitance in AC circuits are subsequently explored. The last and largest part of the book discusses how to analyze all the possible combination of RLC circuits including series, parallel, and combination circuits.