How does a diode function in a circuit?

The function of a diode in a circuit is primarily to allow current to flow in one direction only. This characteristic is a result of the diode's semiconductor properties, which create a barrier that permits electron flow when the diode is forward-biased (the positive side is connected to the anode and the negative side to the cathode), while blocking current when it is reverse-biased.

This unidirectional flow is essential in various applications, such as rectification, where alternating current (AC) needs to be converted to direct current (DC). In essence, the diode acts as a gatekeeper in a circuit, ensuring that current can only pass through in the intended direction, thereby protecting components from damage caused by reverse current flow and enabling controlled functionality in electrical systems.