Zener voltage refers to the specific voltage at which a Zener diode conducts in reverse bias. When the voltage across the diode reaches this level, it allows current to flow in the reverse direction while maintaining a nearly constant voltage. This property makes Zener diodes useful for voltage regulation in electronic circuits. In practical applications, Zener voltage is crucial for protecting sensitive components from voltage spikes. By clamping the voltage to a predetermined level, Zener diodes help ensure that devices operate safely within their specified voltage ranges, preventing damage and enhancing reliability in various electronic systems.