One of the first and most widely used application of power electronic devices have been in rectification. Rectification refers to the process of converting an ac voltage or current source to dc voltage and current. Rectifiers specially refer to power electronic converters where the electrical power flows from the ac side to the dc side.
A rectifier is an electrical device that converts alternating current (AC) , which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification.
A power inverter, or inverter, is an electronic device or circuitry that changes direct current (DC) to alternating current (AC)
A DC-to-DC converter is an electronic circuit which converts a source of direct current (DC) from one voltage level to another. It is a class of power converter.
A solid-state AC-AC converter converts an AC waveform to another AC waveform, where the output voltage and frequency can be set arbitrarily.