Several applications of signal processing are introduced, and then the major topics of the text are summarized. The Laplace transform describes signal waveforms and how a circuit or system operates on signals. Second-order systems exhibit overshoot and ringing, as well as resonance. Frequency response is characterized using Bode diagrams, and filter circuits are designed. Complex systems can be understood with the use of block diagrams, and feedback circuits are analyzed. Fourier analysis describes the spectrum of a signal, and this spectrum is changed by the frequency response of a circuit. Selected prerequisite knowledge is briefly reviewed.