Varistors are passive, voltage-dependent resistive components designed to exhibit a nonlinear resistance that changes with applied voltage. They are primarily used to help limit transient overvoltage conditions by shifting from a high-resistance state to a lower-resistance state when the voltage rises beyond a certain level.

Within the Passive Components category, varistors are commonly recognized as protective elements that respond quickly to voltage surges and help reduce stress on sensitive circuits.

• Nonlinear behavior: Resistance varies significantly with voltage rather than remaining constant.
• Transient suppression role: Intended to moderate short-duration overvoltage events.
• Bidirectional response: Typically reacts to overvoltage in either polarity.