What does the term "reverse bias" refer to in a diode?

The term "reverse bias" refers to when a voltage is applied in the reverse direction across a diode. In this condition, the diode is in a state that blocks current flow. In reverse bias, the p-side (anode) of the diode is connected to a lower voltage than the n-side (cathode), which prevents the majority carriers from crossing the junction and thereby limits the current. This is a critical aspect for diodes, as it allows them to control the direction of current flow in a circuit, acting effectively as a one-way valve for electrical current.

Understanding reverse bias is vital for applications in electronics, such as in rectifiers and clamping circuits, where controlling the flow of current is essential to the function of the circuit.