Pulse-width-Modulation techniques are used for, harmonic elimination and/or reduction at the output of the inverter and simultaneously achieving the output voltage control. Microprocessor based implementation offers many advantages hence stress is to develop PWM techniques so that on-line microprocessor based implementation is easily possible. Different PWM techniques like Square-Wave, Sinusoidal, Regular-Sampled, harmonic elimination PWM and the Regular-Sampled Harmonic-Elimination PWM are the available options for a designer. Depending on the requirements, a suitable PWM scheme is selected. This paper reviews these PWM techniques in details. Their theoretical development and harmonic plots (Harmonic amplitudes versus Modulation index) are presented. The paper also compares all the PWM schemes.