The pulse-width modulation (PWM) technique is applied in the inverter (DC-AC converter) to output an AC waveform with variable voltage and variable frequency for use in mostly variable speed motor drives. This chapter provides an overview of the PWM techniques based on the most basic and classical sinusoidal carrier-based scheme to modern space vector PWM (SVPWM). It is devoted to understanding the underlying relationship between sinusoidal carrier-based PWM (SPWM) and SVPWM techniques. The chapter is also devoted to overmodulation methods. It discusses a comprehensive relationship between the SVPWM and SPWM. For medium-voltage high-power applications, multilevel inverters are employed. Special inverters based on an impedance source network to incorporate the boost function, called Z-source and quasi Z-source inverters, are described in this chapter. Basic topologies and PWM for multilevel inverters are provided. Scopus