This book introduces the foundations and fundamentals of electronic circuits. It broadly covers the subjects of circuit analysis, as well as analog and digital electronics. It features discussion of essential theorems required for simplifying complex circuits and illustrates their applications under different conditions. Also, in view of the emerging potential of Laplace transform method for solving electrical networks, a full chapter is devoted to the topic in the book. In addition, it covers the physics and technical aspects of semiconductor diodes and transistors, as well as discrete-time digital signals, logic gates, and combinational logic circuits. Each chapter is presented as complete as possible, without the reader having to refer to any other book or supplementary material.