What does a diode do in an electrical circuit?

A diode is a semiconductor device that plays a crucial role in controlling the direction of electrical current flow within a circuit. Its primary function is to allow current to flow in one direction only, effectively acting as a one-way gate. This capability is essential in various applications, including rectification, where alternating current (AC) needs to be converted into direct current (DC).

By allowing current to pass through in a forward bias (where the anode is more positive than the cathode) and preventing it from flowing in the reverse direction, diodes protect sensitive components from potential damage caused by reverse voltages. Understanding this characteristic is fundamental in both automotive electrical systems and broader electronic applications, as it ensures the proper functioning and safety of circuits.