A diode rectifier is an electronic component that converts alternating current (AC) into direct current (DC). It uses one or more diodes, which are semiconductor devices that allow current to flow in only one direction. This process is essential for powering electronic devices that require a steady DC supply. There are two main types of diode rectifiers: half-wave and full-wave rectifiers. A half-wave rectifier uses a single diode to block one half of the AC waveform, while a full-wave rectifier uses multiple diodes to utilize both halves of the waveform. This results in a smoother and more efficient DC output.