What is the function of a diode in electronic circuits?

A diode is a semiconductor device that primarily serves the function of allowing current to flow in one direction only. This unidirectional behavior is a fundamental characteristic of diodes, making them essential components in various electronic circuits. When a diode is forward-biased, meaning the positive voltage is applied to the anode relative to the cathode, it conducts current. Conversely, when reverse-biased (the voltage is applied in the opposite direction), the diode essentially blocks current flow, preventing it from conducting.

This property is crucial in applications such as rectification, where alternating current (AC) is converted into direct current (DC). Diodes are also used in signal demodulation, voltage regulation, and protecting circuits from voltage spikes. Consequently, their ability to control current direction is a key factor in the design and functionality of electronic circuits.