A voltage spike is a sudden increase in electrical voltage that can occur in a circuit. These spikes can happen due to various reasons, such as lightning strikes, power surges, or the switching of electrical devices. They can last for a very short time, often just a few microseconds, but can cause significant damage to electronic equipment. To protect against voltage spikes, devices like surge protectors and voltage regulators are commonly used. These devices help to absorb or limit the excess voltage, ensuring that sensitive electronics, such as computers and televisions, remain safe from potential harm.