Here's why:

* Lightning is a powerful electrical discharge: It can carry millions of volts of electricity.

* Power lines and electrical wiring can act as conduits: This means the lightning can travel through them into your home and your appliances.

* Voltage spikes: Lightning can cause sudden, extreme voltage spikes in your electrical system, which can damage sensitive electronics like computers.

How lightning can damage computers:

* Direct strikes: If lightning strikes your home directly, it can cause severe damage to your computer, even if it's not plugged in.

* Power surges: Even if lightning strikes nearby, it can still cause voltage surges on your power lines.

* Electrostatic discharge (ESD): Lightning can cause ESD, which can damage the sensitive components in your computer.

Protection for your appliances:

* Surge protectors: These devices are designed to absorb voltage spikes and protect your electronics.

* Whole-house surge protection: These devices provide protection for your entire electrical system.

* Unplug your electronics: During thunderstorms, it's best to unplug your computer and other sensitive electronics.

In conclusion: While thunder is a sound effect of a lightning strike, it's the electrical discharge of lightning that poses a real threat to appliances like computers. Taking precautions to protect your devices during thunderstorms is crucial.