Voltage transients, or power surges, are an increase in voltage significantly above the designated level in a flow of electricity. The surge in power can be generated by lightning, the utility or by customer equipment.
Surge suppressors operate by forcing the transient energy to ground when the voltage is above a specified value. Depending on what the source of the transient is, the energy being dissipated may be large or small. A layered approach is the best way to prevent transient energy from damaging a home’s electrical system.
A layered approach includes a whole house surge suppressor at the main panel and then subsequent surge suppressors at each device you are trying to protect. Power strip type surge protectors provide limited surge protection due to their small energy dissipation capability. A whole house surge suppressor is a larger device capable of dissipating large amounts of energy. A close by or direct lightning strike will likely defeat any surge protection you have installed due to the huge amount of energy involved.
If you have sensitive computer equipment that requires surge protection, consider installing a battery back-up uninterruptible power supply (UPS). These devices, commercially available at office supply stores, will typically incorporate surge suppression, and electrically isolate the computer from the utility power.